I'm going to delete awful pictures of me from my friends phone.
What kind of pictures are on your friend's phone? Why are they awful pictures?
I am just not a very good looking person, so I don't have many good photos. My friends are also geeks and not attractive.
You can probably just talk to your friend and explain the situation. No harm no foul.
Perhaps I could delete them without my friend knowing.
You can delete them if you don't want people to see them. It's not good if pictures make you lose confidence.