Rainbow Rocks: What Haunts Me To This Day

In the lead-up to Equestria Girls: Rainbow Rocks, Hasbro released some promotional music videos. Some of the songs were really catchy, and I listened to them multiple times. One song was titled "Friendship Through The Ages." During this song, there is a scene where it starts black and then the faces of the mane six characters fade-in and appear. They do this one at a time, as each one sings her part.

It starts like this:

And ends like this:

Now look closely.

In the first image, you can make out the silhouettes of the characters. There seems to be a character between Twilight and Rarity.

Now if you look instead between Twilight and Applejack, you might for a moment think that there is something between them as well. Look again and you realize that we are seeing more of Pinkies body in silhouette. There is no mystery on the right side. Though it is only Pinkies face and shoulders that appear in the second picture, it is clear that there is no person between Twilight and Applejack.

Now lets go back to the left side.

From the first picture you might now assume that the mystery is solved. You might think you're just seeing Fluttershy's dress and legs in silhouette.

Now look again, more closely at the second picture. Look!!!

While Pinkies picture fades below her shoulders, Fluttershy's picture is sharpely cut off. It is obvious to me that something is in front of Fluttershy.

My first thought was that they were originally going to add Sunset shimmer into the picture, but it was unbalanced with an odd seventh character. So I looked more closely at the missing silhouette, and asked myself, is that Sunset Shimmer?

Not a chance. The silhouette has, what looks to me like a bang of hair that cuts into Rarities profile, as well as a pigtail, clearly cutting into Fluttershy's profile. That's not Sunset Shimmers hair, Usagi Tsukino's maybe?

Somebody get Matpat on this, or something. This question has haunted me for so long.

Although, I guess It could just be Fluttershy's tambourine. Maybe?