It looks to me to be "A Boy on a Dolphin", like in that older movie starring Sophia Lorean, I believe..
And with the moveable stem and a rubber gasket, me thinks that is a water valve.
Is there a hole in the mouth of the cherub? If so, that could be a “fountain” fixture that when the stem is pulled up “in the open position”, a small stream of water would spurt from the mouth.