When you open a collection page from within the customizer, you will see the collection page section.
The collection page has a lot of options that you can tweak and modify.
First of all, you can choose to show the collection image and description at the top. For collection images, we recommend going with large landscape images. The theme will try to resize your image at 1620x1080px.
Next, you have options related to the top bar. You can toggle various filtering methods and display useful stuff as sharing options or the collection title. Please note that if all of these are disabled, the top bar will be hidden from the page.
Lastly, you have the appearance options. These are the same as the ones you saw on the homepage sections, allowing you to have a really unique website!
Recommended images size
We recommend uploading large thumbnails with a width of 1024px. We do not have any height recommendations, because our theme uses a masonry grid, so each thumbnail will be proportionally resized. If you want all thumbnails to be square, then upload only 1024x1024px images. If you only want portrait images, than upload 1024x1365px images, and so on. If you want a variable grid with different heights, then upload images with different heights and the theme will do the rest