From My Little Wiki
This unicorn pose has three hooves flat on the ground with the front right hoof raised high. Head is also held up high and faces forward.
Ponies in the Mimic Pose
Milky Way (Euro)
Princess Sparkle (German)
Princess Sparkle (UK)
Princess Crash (UK Princess Sparkle Variant I)
Princess Crash (UK Princess Sparkle Variant II)