For Francisco de Zurbaran, Spanish artist of the 17th Century, painting Jesus on the cross was in some sense the same as standing before Jesus on the cross.  The figure with the palette is said to be Saint Luke depicted as a painter, but surely Zurbaran was painting himself into the crucifixion scene — seeing his witness with oil paints as the virtual equivalent of eyewitness testimony.

I don't know if they do that kind of thing anymore.