Now normally I don't draw ponies with poofy chest hair, but I liked the look it gave Twilight in this video so I kept it for this piece.
Also since I was working with a piece of 8.5" x 11" paper I was presented with a design challenge. I wanted to show all of the Mane Six. However with the exception of Twilight I wanted all of the winged characters in the behind the earth ponies and unicorns so the wings of the pegasus ponies wouldn't obscure their friends.
If I'd been working in my studio I would've done some compositional thumbnails before starting on piece like this. However in this case I came back from a 5 minute break during which time I decided I was going to draw this piece. I looked down at the piece of paper and thought. "Right. What am I going to do for this drawing?" A bit of mental video popped up in my head and I went with it.
I started by laying Twilight out first and then started working in her friends behind her. However when I got to RD I was presented with 2 options. One put her standing behind Rarity and Pinkie where she'd be very obscured, or two put her flying above her friends but further back. I mentally considered possibility of having part of her peering in at some odd angle from around the edges of the paper but rejected those options. So I put RD in flying/dancing in the background. Not perfect but for a piece of compositional spontaneous art it works.