Short for "Gratuitous Picture Of Yourself," usually accompanied picture of yourself, or something that you do. Most commonly used on tumblr both in the main post and as a tag.
Person posts a gif of someone dancing like an idiot, "GPOY"
Person posts a picture of themselves making an awful face, "GPOY"
Free Daily Email
Emails are sent from firstname.lastname@example.org. We'll never spam you.