It is used for a deez nuts joke. You flip it and then you see it.
For example flip stun seed then you'll get the secret message.
by big blue balls. MAH BALLS ARE BIGGER THAN YOURS
This phrase is used to ensnare people into falling for a despicable 'deez nuts' joke, as it reads 'deesnuts' backwards.
It is commonly combined with Pokemon references.
Bob: "Hey Jeff, my Bulbusaur just got stunseed backwards."
Jeff: "What's that?"
Bob: "DEEZ NUTS"