If you can locate a copy of the 1939 CAT AND THE CANARY, that gag of the uncle's portrait having removable eyes through which the murderer spies on the guests is used several times--but the interesting thing is that the "actual" eyes looking out from behind the portrait don't look all that much different to me than the portrait's eyes! Now, if this is meant to represent a bit of business from the stage play by (I believe) John Willard, then THAT may be the origin of the cliche', dating back to the 1920's! (And get the movie if you can, it is available as a bootleg from a number of sources.)