To tell a person that what they're saying or doing is so unlike what they usually do or what they are. Not typical of one's known traits or behaviour patterns.
Eg., A Robin Hood in modern times, a celibate madam of the house, and finally, a priest who doesn't ask for money.

You can't pull it off. That doesn't look right when you do it. You look stupid when you do that. It doesn't look right on you.

nobody never knows you that way

sitting on heirlooms from far away
a dress that was sewn for motherly lives
moths have now eaten its pearly waste
nobody never knows you that way

falling in love is like falling in line
you think what you get back will ease the pain
a strange deal, unspoken, faces entwined
nobody never knows you that way

theres blood and monsters you've taught to hide
and if you behave they wont reappear
yearning for a fleshy way to speak
nobody never knows you that way

the moons and the suns have multiplied
you hear my plea "i'm safe now, i can"
so what keeps you from proving me wrong
"nobody never knows you that way"

Dublin method of adding a rogue 'you' at the end of an insult or statement, derives from Irish (Gaelic) method of putting second person singular after a verb. can be used with any insult but sounds funniest with ones which already end with 'you'. The second 'you' is usually drawn out a little longer.

A rhetorical question asked, usually on social media, to embarrass them with any online content from their past if they ever contradict themselves or have a very unpopular opinion.

The only one that can prevent wildfires.