@TheAmazingPeanuts  
Now I’m lost, are we talking of fan ships or canon implicated ships? XP

@Starswirl  
That was just a simple hug, Ember just blushing out of embarrassing because she isn’t used to being hugged before. Like @Daneasaur has pointed out, one screenshot doesn’t really saying anything then that. I like EmberSpike but I not convinced that screenshot saying anything than new friends hugging.

@TheAmazingPeanuts  
It doesn’t have to. I just wanted to note there was more than just a simple hug. If Marble and Mac’s interaction suffices to be called shipping, then the above qualifies as well.

@Starswirl  
That doesn’t mean anything.

@Daneasaur  

 
And scrunchy-faced blushing.  

@Background Pony #BBB3  
There was more interaction between Spike and Ember in that one episode than there has been with Spike and all 3 of the CMC combined through the series.
 
True “shipping” outside of fan related content requires more to it. While some people like pairing Discord up with Celestia or whomever, the one he reacts with closest and shows tight bonds to is Fluttershy, and while he’s dangerously protective of her, it’s still a “close friendship” and not true shipping.
 
This manner of thought needs to be applied firmly in all cases. What has been shipping in the show?
 
We’ve got Big Mac and Cherilee. Aside from the whole CMC episode, they have been noted together repeatedly through the background to continue supporting their “dating”.
 
Then Pinkie introduced Mac to her “twin sister” Marble and their interaction was quite adorable. Even without words, there was plenty of blushing and flushing between them to consider it shipping.
 
Then we have Spike. Despite him being (apparently) the most eligible bachelor in ponyville to the point that he’s probably been paired with everyone at some point or another, he’s really only been shipped with one character, that being Rarity. There has been his swooning over her, but her affections were returned by nothing short of affectionate kisses from her.
 
Spike with Ember? While Spike pushed for a friendship with her because he knew she was a good person at heart and could be a friend, it ended with a friendship and hug. Nothing wrong with that, but Spike made no deeper indications, much like Discord and Fluttershy’s interactions.
 
Spike with Sweetiebelle? Just about to the point of crack shipping as the two characters rarely if ever share the same screen, much less actually converse with eachother.
 
Basically, while the fandom is free to ship anyone with anyone, remember that those rules don’t apply to screencaps unless it’s VERY heavily indicated.

This is like announcing that Dislestia is canon because there was that flower scene or them in a picture together.  
I’m pretty sure that without narrative focus it is irrelevant moment as they technically never interacted with any dialogs. While this ship would make sense, Ember still has more possibility.

@Starswirl  
Twilight’s pretty much the only one who has changed appearance, but still basically looks the same overall, despite the wings, and height.
 
It’s unlikely they’ll age up the CMC, as I think they want to keep them young, especially so younger viewers can relate to them better. Getting their cutie marks though is perhaps a subtle way to show they’ve grown up somewhat (mentally, at least) sense the first season.

@Beau Skunky  
Aye, that’s all true. So it’s not like it doesn’t happen at all in the show. Some characters do change their appearance. It shouldn’t be too difficult to incorporate such a change either, what with everything being animated in Flash and all. It’s high time the CMC go through their cute and lanky phase, like Applejack and Fluttershy did!

@Starswirl  
That was due to her becoming a princess, who tend to be a li’l taller then an average. The show poked fun at it once, I remember. “I am not that tall!”
 
It’s very rare for young characters to ever grow physically during the duration of an animated show, because as you said it would require changing their appearance, voice, and such. Only one I can think of was Joseph from “King of the Hill.”

@Keith Mowz
 
@Beau Skunky  
On top of all that, there has been a subtle change in Twilight Sparkle’s bodyshape. Could be that the animators choose not to have the CMC grow because it would mean having all the other younglings grow too, like Diamond and Silver Spoon and so on.

@Keith Mowz  
I gatta admit, I actually think the new “big eyes” look better, and cuter then the dot eyes.
 
@Starswirl  
Truth is, most cartoon children are that way. (Bart & Lisa in the Simpsons had different birthday episodes where they turned 10 & 8 respectively, and remained that way for over 20 years. Not counting the “possible future/flash forward” episodes.)
 
Ironically, sense the CMC’s voices are no longer little, they do sound noticeably older/different though. (In fact, Bloom & Sweetie now sound a li’l strained to sound younger nowadays, much like Scootaloo’s raspy voice) Other fillies like Diamond Tiara & Spoon were voiced by women in their 20s, so it’s not usual for girls to voice characters much younger then they are, as it’s easier for them then boys/men. (In fact, they had to replace Pipsqueak’s VA, sense his voice hit puberty.)  
In an episode or two last season, I recall surprisingly, the CMCs voices actually even voiced a few bit/background characters who were grown-up ponies, and many fans didn’t realize it was them.

@Starswirl  
As are Pound and Pumpkin cake. Cursed with the dot eyes that seem to be retroactively being removed from continuity otherwise, what with AJ’s baby photo and Flurry, though they do seem to be acting more like toddlers now.

@Daneasaur  
Rohan Kishibe is 20. >w<

I cant put any of the mane 6 above 20.
 
The whole cutie mark magic automatically gives them a vocation and the talent needed to live independant lives at very young ages.
 
Thats why the equestria girls still need to go to school while their equestrian versions already have jobs and live on their own.
 
Ponies just seem to go to kindergarden and elementary school at most before magically getting their CM and going out on their own.

@Keith Mowz  
Aye. They should’ve grown physically by now, really. Applejack was not much older than Apple Bloom but still looked lanky and tall. The CMC are frozen in time, it seems.

@TheAmazingPeanuts  
One of the “unconfirmed yet confirmed” things that was said was that the mane six were supposed to be “late teens, early twenties”. I would put Twilight at the tender age of 6-7 at most when she hatches Spike’s egg.
 
So lets do some math here, if she’s 6-7 years older than spike and is… lets take a guess at 18 when the series starts, Spike is about 12-13.
 
But if Twilight is older than that and is, say, 21, this would make spike about 15-16.
 
Spike attitude would put him more towards the mid teen range.  
>he doesn’t find girls “icky” and honestly finds one of them to be downright gorgeous to the point he’s trying to woo her  
>is mature enough to know the difference between a crush and real love (the episode with trenderhoof)  
>has game nights with the only other local mature male around (Big Mac)  
>never spends any “free time” with any of the little ponies and when he does interact with them, he’s treated as an authority figure
 
He still does immature things now and then and occasionally rebels, but what teen doesn’t?
 
I also age Rarity around no younger than 25 for how successful her business is.

@Starswirl  
Applebloom is already a filly old enough that is was very unusual they didn’t have cutie marks yet, and they got those a decent while ago even in-universe.

@TheAmazingPeanuts  
Just to note: Granny Smith said Applejack and MacIntosh were only a little older than Apple Bloom when that episode happened.

@neo4812  
I very much doubt that Rarity is that old than Spike, but like I said earlier in the comments, it don’t really make a difference anyway since he will probably outlived both Rarity and Sweetie Belle in the end. Since the show is all about friendship and not about romance I doubt Spike will be with anybody at the end of the show.

@neo4812  
Or aged like fine wine.

@Cabrony  
and rarity will be an old hag

By the time sweetiebelle is old enough for Spike he will be old enough for Rarity.

@Prof.NightJack  
Yes, we don’t know how old the characters are in the show. But the data is pretty obvious: Spike never spends any real time with the CMC and when he did during “Just for Sidekicks”, they treated him like a authority figure, not their equal.

@TheAmazingPeanuts  
Do we have a time line for how long after them getting their cutie marks/Spike hatching and the flashback in “Where the Apple Lies”?  
No we do not, it’s guessing at how old they are at eatch point.  
So if someone thinks Spike is closer to the CMC in age they are no less correct then someone thinking he is closer to the mane 6.  
Until we have a canon time table both are just as right.