It sounds as though you may have accidentally added an entire photo collection instead of individual photos when using the Aura App.
To determine whether this is the case, first you need to locate all of your selected photos by tapping into the "Added" section in the Aura App. Next, tap on your frame name to view Collections at the top and individually selected photos below.
If there is a "Collection" of photos that you believe may have been selected by mistake you can simply remove the entire collection by tapping where it says "Edit" and deselecting the frame to which it's been added.
There is also an option to "block" the photo collection entirely or "hide" individual photos from the collection. To do this, tap the icon on the top right (three small dots) where you will see the option to "Hide Photos" or "Block Album." Selecting to "Hide Photos" will allow you to check and remove individual photos from a collection however "Block Album" will remove the album entirely.
If you don't have any photo Collections selected for your frame perhaps you'd like to remove individually added photos. To do this, tap the Edit button below where it says Individual Photos and select the photos you'd like to remove before tapping "Hide Photos."
If you require further assistance please don't hesitate to contact Aura's Customer Support by emailing firstname.lastname@example.org or calling 646-630-7237.