Bel (aka Belus) was an ancient Mesopotamian deity. The temple complex at Palmyra destroyed by ISIS a few years ago was dedicated to this deity, who may have been a sun god.
Motte based this painting on a quote of the ancient Greek philosopher Herodotus, which stated that in Babylon there were daily beauty contests and the winner sat on the lap of Bel’s statue overnight before being offered. Presumably the lions below will eat her up in the morning.
It was later discovered that the quote was invented and not actually written by Herodotus, so it’s likely that this daily ritual never took place.