A head-and-shoulders portrait, slightly to left, in black with a dark brown full-bottomed wig. The background is plain brown with one fluke of an anchor appearing on the left, where it is also initialled 'JG'. Another version of this painting exists.

A pupil of Lely, Greenhill in his early work showed a dependence on his master that he later overcame. His early death by a drunken accident cut off a promising career.