My Little Pony: Friendship is Magic - Image #385,240

Well, that keyboard explains Sweetie Belle's online activity.

From the same Tumblr:

My theory is that the keys work like 8 directional d-pads; if you include the neutral position as a valid position, that gives 81 characters + space.

Alternatively, not shown in the clip if there are floor pedals for the back hooves, which would further expand the keyset.