From "Crochet Workshop" by James Walters, it's a black-and-white photo of the author. I like to imagine this in color. Oh, the exuberance of it all!
Crochet Workshop was first published in Great Britain in 1979. My much-loved copy is from 1983. Fortunately, this valuable resource for crocheters is readily available again, having been re-printed by Dover Publications in 2014