“A couple trying to get intimate but the tattooed male is distracted by the smell from the love making couple in the other room.”
Look at the woman trying to pinch the nose of her man so he does not smell. The other woman is trying to clean the man’s penis with tissues while he has already penetrated her.
The crowded quarters of illegal brothels meant that there was absolutely no privacy and very little room - at best prostitutes and their clients were divided by sliding doors or a screen.
Reference: p.179 (Ill.66b) in Japanese Erotic Fantasies - Sexual Imagery of the Edo Period by C. Uhlenbeck and M. Winkel
The title Ama no ukibashi is a reference to a bridge famous in Japanese creation mythology as the place where the gods Izanagi and his wife and sister Izanami shaped the world. Izanagi threw a spear into the sea and when pulled out, the water dripping from it formed the first island of the Japanese archipelago. Izanagi and Izanami were also the first couple to have sex and procreate.