I would assume that the people who have the money to spend on in-game purchases are adults.
So why not make the game's branding appeal to adults?
As for the actual image, it looks like a fantasy pony with an ice cream cone stuck on its head. The game's earlier designs in particular are highly detailed, intricate and imaginative. They've declined recently and the new ones don't move, which is disappointing, but the last couple of icons still don't represent the best of the game's art.