Your site doesn’t work for me on a desktop.
I noticed that you are using a size of 60×60 for your thumbnails. How did you pick that size? It is not among the list of SmugMug’s accepted sizes, and so it will not show up in Photonic’s dropdowns. I currently don’t have code that supports custom sizes either. I have some code that I wrote 7 years back to handle custom sizes, but that was for the old SmugMug API. While that might work in some cases, I think you are using authentication, and all your thumbnails are coming up with a “Not found” error. On your desktop you are already authenticated with SmugMug outside Photonic, so you might be seeing the photos. But since the custom size code in Photonic is not correct, you might be getting an error on unauthenticated devices, like my computer or your phone.
Try picking a size from Photonic’s dropdowns – that might help you.