"Sweethearts" Playing cards

Here is another deck of "Smart Set" cards. These feature a photograph called "Sweethearts", attributed to R Hill 1907. I don't know when the deck was issued but it was sometime between 1907 and 1917, as it has a 2cent tax stamp on it. (tax was 2 cents per deck from 1894-1917).

I have another deck put out by Russell that features the same photograph but with an ornate border around it.

Does anyone know anything about the photograph? Was it taken just for these cards or was it a popular image that appeared on many items? Google search of "Sweethearts R Hill" fruitless, other than references to these cards.
Thanks!