Steven Aquino, writing at The App Factor:

What I’d like to see Apple do is not necessarily make the emojis themselves bigger — the keyboard only fits a finite space, after all — but rather change how they’re presented to the user.

Here’s my suggestion: Apple should take the magnification animation it already employs on the text keyboard and apply it to the emojis. Every time I press on, say, a smiley face, the face would “pop up” in the same manner a letter does when you press its corresponding key. Taking this a step further, it would also be helpful if you could use the magnification loupe (for moving the insertion point) to scrub through emoji. The only caveat here is that Apple would need to make the loupe larger, which is something I wrote about in my aforementioned article. As it is now, the current magnification level wouldn’t do much good to compensate for the small size of the emoji.

Looking at the emoji keyboard from an accessibility perspective, Steven’s suggestions make a lot of sense. Existing features such as Dynamic Type and Character Preview could also be used for emoji, but I like Steven’s loupe idea better.