Someone who is seen as generic and one dimensional, with little depth or individuality to their character. Typically someone who strives to 'fit in' to be as popular as possible, often not being their true self. Can also simply mean someone who is seen as being a stereotypical character in any kind of way.
"My friend only watches Reality TV and makes fun of anything that isn't the current fashion........he's a real cardboard cutout c**t"
12 step recovery jargon referring to someone new who talks about how great life is, now that they'resober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.