in photo document the anti-aliasing is turned off - you can see that if you insert the default bitmap and zoom in - in a photo document you can see the steps in the stripes in very high quality and high quality as well as full colour views

in other words the vhq/hq is over-ridden in photo document and it is the equivalent of full colour in an ordinary document

I am not convinced there is any difference between photo document and an ordinary document in full colour view, including bitmap copies - I don't see any when I try this