Thwarts (benchs) are too far apart and the high heels lack credibility. Footrests are needed for serious rowing. Finally, it is not practical to chain the rowers to the oars, as the oars have to be shipped when coming alongside a harbor.
They better be careful, the nipple rings are large enough to get caught in the chains. If they get hurt, I'm sure he Captain will pay extra special attention to the affected area, to make sure it heals properly. Plus frequent followups over the next few weeks.
Maybe their Master decorated them so they could ARRIVE in port, and proudly display themselves in a manner that says "Look at what MY MASTER owns". They could be very proud Galley Slaves and love their Master very much.