This is a less rude, subtle approach to curb someones bragadocious behaviour during conversation. It limits the chance of copping a smack in the grill from the offending party.
Hey wigga, i know your missus is a pornstar and your best mate is the lead singer of N'Sync but im sorry unfrotunately i think you might be bordering on bragadocious.
Referering to a person whom is quite far from the definition of cool. Praising one's awesomeness in a mocking/sarcastic way. Refering to the jaguar (being the coolest of all cool cats)