Change the end of the filename from .thumbdata3-xxxx to .jpg . it with any standard photo viewer. 2. Use RS File Manager (Android)
I can give you a step-by-step guide for your specific device.
A: Generally, no. They contain a visual history of images that were on your phone. Even if you deleted the original image, the thumbnail remains. If you are selling a phone or transferring files, it is best to delete the .thumbnails folder entirely.