You certainly can remove or edit photos that have been contributed to your frame.
First, you need to locate the photos that have been contributed to your Aura Frame. To do this open the Aura App and click the "Settings" icon on the top right. Next, tap your frame name and under Family Share click on the person whose photos you would like to remove or edit. Here you will see all the photos that have been selected for your frame by that particular contributor.
To remove a photo from your Aura Frame tap the icon on the top right (three small dots) and select the option to 'Hide Photos'. Next, check the individual photos you would like to remove and confirm by tapping 'Hide Photos.'