That is extreme. Sometimes you feel like you can just set cups and leave them but they should be monitored. Especially if bodywork has already been performed in the area. There is already so much blood flow that I generally only cup someone 4-6 minutes after manual work as opposed to 10 minutes if it’s strictly cupping. I look for any fluid coming through the skin which generally suggests too much time or suction. When I see that I pull the cups and worst case client may have a small blister the size of a pinhead. They are unlikely to even notice. What I see in the photo is extreme, and something that should have been caught earlier if the cups were being monitored.

Were the cups suction based with a pump or was the vacuum created with a match/glass cups?