Not a porno.
I found this antient (1914, despite what the cover says) yearbook from Colgate University:
The cover, but not the pages, is made of leather. The image at the top is a (probably hand colored) photograph print cut out and pasted on. Because of the way it is bound, I cannot get good interior photographs without unbinding it or destroying it.
Note the odd “underbite” on the G in Colgate, I have not seen that in a font before.
None of my ancestors attended Colgate that we know of, so how this came here is a mystery.