Looks like she’s setting up an arm bar, though tough to tell without being able to see her left arm and weird that she’s not gripping anything with the right. Could be coming from a closed guard type position (with him between her legs) and then pivoted to get the arm bar. It’s entirely possible she just let go of both arms to give/receive instruction.

Edit: Although yeah…doesn’t make much sense for her left leg to be on the ground then. Who knows…