A camera's zoom changes the focal length of the lens, and thus the angle of view and picture frame; whereas the zoom feature in a graphical user interface typically changes the view of a document.
the interpretation of a request like zoom in on the man depends on context: as a standalone request, it probably represents the intention of changing the picture frame; but in interactive dialogue or as part of a multi-instruction sequence, it could indicate a request to change the view of the image in the editing interface.