Where can I find ALL pictures/videos of most recent backup/autosync?

Hello Everyone,

My friend has a WD My Cloud and I was using the application on my phone to go through our photos. However, when I tried to download some of the pictures, I was asked to confirm access to my photos. Doing so ultimately led to ALL my photos on my personal phone to be synced/backed up and have now been uploaded. I was able to notice because random photos from my phone were found in random folders.

Is there any way I can reverse this process as I do not want to have any of my photos ‘backed up’ or synced to the drive. Where can I find my MOST recent backup/uploads so I can delete them? I can’t seem to figure it out as my photos are all over.

I would really appreciate it if someone can help me out - I have absolutely no experience using My Cloud. Thank you in advance.