a 'deeply in love' man with his fiance sitting at perk bench?
No, it's just his pet dog .. If you watch the front view you can easily identify that. The dog can sit like human beings and have hair styled like lady .. so, the picture from back view turns out to be a fake illusion.
fake couple illusion
BTW, it's originally from the June 16, 1967 issue of Life Magazine, and shows Paul Barton and his dog, Denza. [source]