Virgil Finlay (1914-1971) lived and died by making swipes from the other artists, photographers, that is, who took pictures for the sake of art or commerce. (Those two fields are not, of course, mutually exclusive.) However, I don't know him to have swiped from other illustrators or draftsmen. Until now. But this one is a little tricky. I'll go through it step by step:
First came Finlay's black-and-white interior illustration for Pearl Norton Swet's story "The Medici Boots," published in Weird Tales in the August-September issue of 1936:
Next came Harold W. McCauley's (1913-1977) cover illustration for Imagination: Stories of Science and Fantasy, from May 1953. Although the pose is similar to that of the conjured spirit in Virgil Finlay's illustration above, I would not call this necessarily a swipe by McCauley:
But Finlay's cover illustration for Weird Tales, Summer 1973, published posthumously, is at once an update of his drawing from nearly forty years before and a swipe of McCauley's cover. It's not a straight swipe, though, because Finlay rotated McCauley's Shiva figure slightly, recolored it, and recast it as a kind of Medusa or Gorgon figure:
So what do we call that? A swipe of a swipe? I'm not sure. Another possibility is that both Finlay and McCauley swiped their pictures from an unknown original source. That may actually be the best explanation. On the other hand, it could be that, as the wise old owl said, "The world may never know."