You shouldn't judge others on their appearance.
Katie tended to judge everyone she saw by how expensive thier clothes were.
Katie wants to invite people to her party,.
Katie decides to talk to the people and figure out who she wants to invite from that information.
Katie invited only those who wore expensive clothes all the time.
Katie is surprised that some of the most interesting people wore the same cheap clothes every day.
Several of the people she invited weren't fun or exciting to be around.