
Ishmael was sixteen years old when he and his mother were cast out, an adult in ancient society, but a lot of artists like to make him a baby or a little boy, to emphasize the pathos.
And to avoid having to draw muscular men.
Simone Cantarini (1612-1648) compromises. Ishmael is that chubby baby in the background, dying of thirst while a naked, muscular male angel is appearing to Hagar.

At least Jean Charles Cazin (1840-1901) gives us a nicely shaped bum.
As does Edward Sheffield Bartholomew (1822-1858)
Fidardo Landi (1865-1918) skips Hagar and concentrates on Ishmael.
In the 1994 movie Abraham, Ishmael is played by Giuseppe Peluso