Hi pior,

re:
> Why not simply put a button in the UI for this mode switch, next to Add/Remove/Align/Hide ?
> This would make it easily discoverable.

It's because the same behavior exists for the edit frame being used to modify regular geometry. It's not specific to just image editing.


> The question of how to snap to the corners of an already placed image object remains though. Is there any know workaround for that ?

When you are in the image command, points for added or edited images will already snap to other image corners.

If you want to snap geometry to image corners outside of the Image command I'd recommend placing a rectangle down before placing the image.

- Michael