Hi Sarah, Thanks for contacting us! This is happening because our collage maker currently doesn’t allow you to Zoom Out to a level that would allow the edges of your photos to become visible. You can work around this so that more of each photo will be included, but you will be able to see the edge of the photos (which will make them no longer appear circular).
To include more of each photo, first open up each image and crop it to a square size (using the Basic Edits tab > Crop tool, with the preset dropdown set to Square). Next you can also add a border to each image using the Frames tab > Border tool, with an Inner Thickness of 0 and the Outer Color of your choice (probably the same color as your collage border). You may want to experiment with different border sizes. Save each image so that they save to your Ribbet History.
Then when creating your collage you can change the Photo Basket to view your History items, and drag on these edited images.
Let us know if we can be of any further assistance!