Hello Jacob Williamson,
To categorize images in the grid gallery you need to come up with categories for images and then create them by using tags:
1. Go to Image list.
1. For each photo on the Image list choose Categories tab.
2. Enter the name of category.
3. Click “”Enter”” to create a tag.
We can create multiple tags for one image, thus each image of gallery will be displayed not only in “All” category, but also in their categories.””
Besides to you can set the order of categories on Categories tab in gallery properties.