I just did this for a different surgeon's office because I'm also doing a long-distance consult. The pictures have to be nude from the waist up but do not need to show your face. They cannot tell anything about your chest if you're clothed.
I took four pictures because I had to take them in a mirror with my phone cam. If you have a SO or willing friend/ relative, that would be better but I think mine worked out fine. I took two frontal pictures - one with my arms raised and from directly front-on; the other with my arms to my sides and a bit of an upshot. I then took two profile pictures (one each side), one with my arms raised to shoulder height, the other with my arms raised to mid torso. You should also include (regardless of if that ask for it) your basic measurements (weight, height, bra size or measurements if possible).
I uploaded my pictures via a file-sharing service that doesn't require an account (only the link) to access, and sent the link to the doctor's nurse with whom I'm in contact. You could also simply send it as an attachment. Make sure that the photos are well-lit, and that you've cropped them to your comfort (I cropped out my artwork that was in the background, for example). You *can* opt to include only your chest but I included most of my upper body so that the doctor could see how I carry both fat and muscle.
Hope this helps! It looks like we're in the same boat; pass me an oar, will ya, mate?