Man from Hamburg, Germany
What it is:
Cabinet card measuring slightly less than 4 x 7.5 inches.
What I know about it:
Photographer is Brenning of Hamburg, Germany. Otherwise undated and unidentified.
Comments:
A dapper gentleman with a bold mustache, long coat, top hat and cane. (Yes, his being from Hamburg would make him a Hamburger, but let’s not go there.) Interesting that one of the props on the table, besides a pair of books and some sort of chalice, is a photo album (it’s the same word in German and English).
Pics of Then 
With the right hat, with the right mask, he could be the Hamburgler.
And a cape and a horizontally striped shirt!
Judging from the tiny collar and fit of the coat, I’m going to guess 1880’s, but it could be later. I’m disturbed that he seems to have no tie–yet does sport a silk pocket square! Note also the massive pinky ring. Who is this person??