Looking at the newsfeed on Facebook and coming accross a status update where the writer is welcoming likes or comments but no-one does. Therefore 'liking' the status, not because you actually like it but more that you sympathise with its creator.
Penelope: "Dude, did you see Karen's last status update on Facebook...?"
Patty: "Yeah it was not funny at all, what was she thinking?"
Penelope "I have no idea, I felt so bad for her though so I pity liked"
Liking someones status, not because you actually like it, but because you could tell that the person tried hard to write it and expects people to like it.
Meh, that status is kinda lame, but I could tell that Sally thought it sounded really cool when she wrote it. I'll just pity like it.
When you like someone's status/picture on FaceBook because they're 1) trying too hard, 2) desperate for attention, or 3) just weird and you want to be the one they save when they come to school with a sawed off shotgun.
Person 1: Dude, did you see Kayla's status she posted last night?
Person 2: Yeah, it was so dumb I had to give it a pity like.