From a suggestion on mw.org:

Problem

Users may not be aware that the image can be interacted without appropriate controls.

Background

Rotating an image automatically allows one to view it literally from another perspective. This is something that is currently impossible with most other video formats and should be taken advantage of.

Proposed ideas

Add a new wikitext construct to 3d files, .e.g [[file:abc.png|rotate=true]]
Add a keyboard shortcut to initiate and stop rotation (see Extension:3DAlloy)
Add a button to the Multimedia viewer to initiate and stop rotation.
Add some help info indicating what can be done with the object.