OK, so for that specific mask it is a lighter mask and has a folded texture to it so it might look/work a bit different than some other masks. Most of the templates in this set are designed to look like the photo is 'spilling' out of the frame. So in most cases, you will duplicate the photo and clip it one to the photo mask layer and one to the photo spill layer.
Here's what I did:
1-Clipped the photo to the Photo Mask Layer
2-Duplicated the photo and clipped it to the Photo Spill layer
3-On both photos I changed the Blend Mode to "Multiply".