Updated
A watch buyer reads the photo like a spec sheet. Hour markers, sub-dials, the finish on the case, the crown and the clasp all get inspected, and at higher prices a single soft detail is enough to send them to another seller.
Watches are also mirrors. A polished case and a sapphire crystal pick up the studio, the camera and the photographer. Most of the craft of watch photography is deciding what the metal and glass should reflect, then making every watch in the range reflect the same thing.