When somebody ignores/pretends you don't exist. Almostas if they're telling you to go fuck yourself, but without actually saying it.
Person 1: Hey there! How are you doing?
Person 2: ...
Person 1: Soo.... what's up?
Person 2: ...
Person 1: Well I guess i'll just go fuck myself, then.
When the situation is awkward or you dislike the idea of something due to it being awkward or unusual; you then feel as you become paper thin or a cardboard cut out.