Beginner Question: Resizing Images in Gallery

I’m not sure what i’m missing when i read the googled instructions for Wix, but i’m finding a lot them to not be very intuitive. For example, i’m using a collage gallery for my site. I wanted to know what determines which images are shown as full sized and big and which ones are small. This isn’t very clear. I google how to resize images for further clarification and come across this.

https://support.wix.com/en/article/changing-the-size-of-images-in-a-collage-gallery

I’m not following this. There is no layouts icon on the page. There is layouts in the settings icon for the gallery. Is this what the page above is referring to. I click into it, and i can’t resize individual images. Am i to understand that the collage gallery randomly picks images it wants to display as big and small?

Thanks,

Your question is for Wix Support and not the Wix Code Forum.