When viewing the tree a red dot above the person's name indicates one or more photos. It is good to see at a glance which entries have a photo, but would be better to also see at a glance which entries have multiple photos. This could be done simply by using a different color of dot when there is more than one photo.
Since I often look for entries of more than one photo this would save the time of needlessly opening a person's details followed by opening the Pictures tab only to find just one photo.