When you claim you dissapear, or you claim something is there, when it really isn't, due to it being imaginary, or you wishing you were imaginary.
Example 1 -
Person 1: You didn't lock your door, aren't you afraid someone is going to take it?
Person 2: No, it's in Unicorn Mode; no ones going to find it.
Example 2 -
Person 1: I have a million dollars, dude!
Person 2: No you don't... where is it?
Person 1: In Unicorn Mode, you can't see it but I can.