[yoyo1999]

I'm mostly a programmer.

I used to do a similar thing on Basecamp. Annotate the picture with OS X's Preview.app and then drag and drop to upload it.

Collect the textual feedback and then upload a new work again. Repeat that for like 10 iterations.

Also, I upload the works for remote peer reviews. Not real-time client reviews.

In those cases, there isn't a strong advantage in using Red Pen.

Just share my thoughts.