Edit: the middle panel is technically the first, and the top and bottom are the second.
Pinkies eating dashies hair like a pancake and for rainbow pinkies leaning on her like a fallen tree.
MY only question is why they're sleeping together in the first place. Are you now playing the shipping game, Otaku?
I was thinking about if you made two lines in an 45 degree angle to vertical, going top left -> bottom right, and the placed the two line around the middle picture as bases for the dividers, then I think the viewer's eyes would be drawn to the center picture first. I hope this makes sense outside my head!