in the background we see Madoka and Homura (which is probably bittersweet for Homura).
We see Sayaka pulling Kyoko away from Mami and toward the other two.
The witch runes on the sign above read "Friends Only", which emphasizes Mami's loneliness.
On the left we see a picture of Kyoko pulling Mami by the hand (which I believe may be one of the covers from The Different Story) and the promise that Madoka made to Mami in Charlotte's labyrinth, as well as what appear to be the soul gems of the other four girls.
On the right we see Mami and Madoka walking through Charlotte's labyrinth and an image of Charlotte from when she first manifested and sat in her chair
on the soles of Mami's shoes we see Charlotte's symbol.