On the walls of the main shrine inside the Hemis monastery are paintings in the usual Tibetan Vajrayana Buddhist iconography. The first was a painting of the three powerful deities who helped Guru Padmasambhava to pacify the demons who were troubling the mountain kingdom. The most powerful of them was the central figure of the Yamantaka. I’m not an expert in this iconography, but I could tell him by the water buffalo which he rides (the buffalo seems to be somewhat weighed down by him). All these pictures are meant to educate, so they designed to be easy to interpret.
The Yamantaka is often shown as devouring a snake, which denotes time. This is a symbol which emphasizes that he conquers time, and illustrates the meaning of his name, the conqueror of death (Yamantaka = Yama + antaka in Sanskrit). Here he holds a snake in two hands. Interestingly, he is the aggressive aspect of Manjusri, the Bodhisattva of learning and wisdom. That’s a bit esoteric, but it is meant to show people how to conquer death.
I should have taken photos of all three of these deities, but I only have this other photo of the painting which shows the wrathful aspect of Palden Lhamo (whose name in Sanskrit is Shridevi). She has many aspects as a guardian diety, and again, one of her attributes is wisdom and learning. Hemis monastery belongs to the Red Hat school, so she is given a secondary role. In the Yellow Hat (Gelug) school she might have had the central role.