Unfortunately I don't have a print of this photo in a book so I have to go on the attachment. I'm not sure, but think I can see a shadow of the flower just above it.

Assuming this is correct (not just my dodgy eyes), I would guess that this is a photo taken of a distorting mirror (so we're seeing a reflection), and that it was a long exposure during which the tulip sagged a bit (so we see a bit of before, but mostly after). A better print may disprove this theory though.