Tai Chi Mirror Image Form

Though most people only learn one side of the Tai Chi form, it is possible to practice all the moves in "mirror" image, i.e., switching sides. This short video is composed of live action and still photographs that capture part of a Mirror Image demonstration. Can you tell who is doing the regular side and who is doing the mirror image? (Both are. Michel is a reflection of Lilian and Lilian is a reflection of Michel).