I'm not sure where I got it, but it's very strange. It looks like someone took a photo of Billy Sullivan Sr in the field, printed the photo and then cut out his outline from his ankles up, placed the outline against a white background and re-photographed it.
Someone wrote "Sullivan, Catcher, Chicago Americans" and "673-15" on the top. My guess is that this was written around the time it was printed, since its my understanding that people stopped referring to the Sox as the Americans in the early part of the 20th century.
The back says FROM GEORGE GRANTHAM BAIN (the last name is a bit muddled so that is my best guess), 82 UNION SQUARE EAST, N.Y., This Picture not to be re-sold, for your use only, Mar 31 1909
and then there is the number 4237 in the corner

It's aboout 4.5" by 6.5" in size
Any ideas of what this is or why someone would cut an outline like that and then re-shoot it?