Medieval and Renaissance Christian and secular artists had no religious restrictions regarding depictions of Mohammed, and were free to show his face and body in their entirety.
This picture is of an early Renaissance fresco in Bologna's Church of San Petronio, created by Giovanni da Modena and depicting Mohammed being tortured in Hell.
The fresco is in an inaccessible part of the church and is now only visible at an angle from a distance; this old black-and-white image is one of the few official photos ever taken that shows a straight frontal view of the figures.