On the right, they're being stoned for their lies on the palace terrace. In the middle, Susanna is just innocently enjoying her bath, surrounded by her maids. The palace in the background is an amazing work of imagination, showing off Altdorfer’s skill in architecture. He was one of the first to use two-point perspective in German art, inspired by Italian styles.
There's even a rough sketch (now in Düsseldorf) that’s slightly different from the final painting. The plants also play a role in the story's message—the mullein by the staircase symbolizes Susanna’s bravery, while the nettle bush points to the men’s wicked desires.