Muffin is napping and a hand starts petting her.
The hand moves from her head onto her back and she starts to lift her rump.
The hand moves to her rump and she has stretched out her back legs to raise her rump fully.
The panel depicts a graph: GRAPH OF CAT PLEASURE VS. POSITION OF PETTING HAND
The graph line overlays the image of Muffin's body with the head on the ground and her rump in the air.
Happy Labor Day! I hope you don't have to work today, or if you do you get paid well for it.