It is CRITICAL that you add the ability from desktop for the trainer to view any client's photos side by side they wish.

For example i wish to manually select the starting picture from jan, then the midway point from feb then a current photo today in march

Then be able to compare the 3 "front" photos side by side in a "scroll bar" fashion. or any two photos of my choosing, or any number of photos that I manually choose to compare.