I came across an expression, “If not impossibly so” in the review of movie, “Magic Mike” under the title of “The body politic” in New York Times (June 28). The phrase appears in the following sentence:
“The hard-working Mr. Tatum is scarcely non-Hollywood. – He’s pretty, if not impossibly so, with the looks of the heartthrob next door and the wrestler’s neck, jug-handle ears and smiles that help bring him down to earth. Unlike Matt Damon, though, Mr. Tatum hasn’t yet played smart on screen.”
I understand ‘If not impossibly so,’ is a phrase to show the author’s reservation from making a conclusive remark, but I feel somewhat redundant and circumlocutory in this double-negative construction.
What does “If not impossibly so” exactly mean? What is the added value of using this phrase? Is this a phrase used in your daily conversation?