A person who doesn't flush the toilet after a bowel movement in hopes that someone else will stumble upon and be able to admire their work of art. Some hard-core excrebitionists have been known to go so far as to refrain from wiping in order to avoid obstructing the view.
An exhibitionist who goes too far, i.e. spams private groups with their shares, shares kink without others' consent, makes less secure exhibitionists feel mediocre
"Bitch is posting so much gonna get banned for being an extrabitionist!"