This is one of my favorite photos; obviously I'm not the only one since you can find it all over the 'net(I found mine on Scott Saavedra's Comic Book Heaven blog--thanks Scott!).
I'm not sure what this photo was shot for--it's obviously staged, since that is not Boris' daughter Sara, but its way too early for her to be a grandchild. From what I've read, old Boris was a kind, agreeable fellow, so maybe he just liked comics--he did have his own series, after all.
Judging from the covers, this photo was taken sometime in early 1958, right around when he was making Grip of the Strangler and the confusingly-titled Frankenstein 1970.