Twilight Sparkle in EW clip
In some of these shots she lacks wings, including the high quality promotional screenshot EW used as a header.
I watched this like five times then just decided to take a screen shot of all of Twilight’s appearances (except for one shot of the back of her legs where her wings would not logically be visible) and these screenshots have made something clearer to me
Different stages. The repetitive nature of the shake your tail song and some really, really good editing made me unable to see them as two different performances and I was about to write my theory off as an animation error until I took these, but look carefully. Winged Twilight’s stage doesn’t have the more childish back drop, Pinkie’s drums are green in those caps too, while they are blue in the wing-Twilight ones.
Human Twilight is gonna be a thing and she’s probably going to have to earn her own wings, or we get a last minute visit from out Pony Princess :D Who knows?