"Cutline" is jargon for "caption," the text accompanying a photo.
Cutlines are normally written in present tense.
They should generally identify everyone recognizable in the photo. People are generally identified in order from left to right. But exceptions are made, for example, if a specific person is more prominent.
- Creating Captions They'll Love, by Jack Mulkey of the Daily Breeze, Torrance, Calif., via the American Copy Editors Society
- Writing Better Cutlines, by Raleigh Mann, retired from the University of North Carolina at Chapel Hill