Add label to the images in a linked gallery in Photo Stack

Because my linked single images trigger various galleries, I need to label the images in the grid. For instance, an image of a paintings of a person will open the Portraits gallery. How can I label the images that trigger hidden galleries in the Photo stack? I’m using Foundry, and nothing I’ve tried works for more than the 3 columns I set. Try 6 galleries linked to single images and it places all the text together, under all the images. Putting two complete Photo stacks together renders the images invisible, though the tags, labels or buttons are still there. It’s perplexing. Any help appreciated. Thanks, Brenda