If you couldn't imagine Margot Robbie as Tonya Harding ... you will now, 'cause she NAILED the most awesome Tonya line ever during filming.
This clip from the behind the scenes of the Tonya movie seems to be recreating one of her many infamous moments ... when Harding got pissed at U.S. Figure Skating officials ragging on her outfit.
If Margot isn't the perfect physical fit for the role ...she's definitely got the mouth down. It's unclear if Tonya really did punctuate the argument this way -- but if she didn't, she'll wish she had when she sees Margot do it.