A cousin of mine told me that this was a pose that Uncle Dennis used often and that it ran in the family!
On the back of this photo is written, “Dennis King starred in “The Greatest Man Alive”. This dates it to the late 1950s; to an opening night of May 8th 1957, according to the New York Times, which started a review of the play with the words:
PROBABLY Dennis King likes to act. That seems to be the only way to account for his presence in a feeble jest like “The Greatest Man Alive!" which opened at the Ethel Barrymore last evening.
There is no indication of who took this photograph but it is from a batch that appears to have come from a theatrical agent.