Above the bearded man's head is a framed map, an allusion to the maps found in Vermeer paintings. I would've missed this detail without Flam's guidance -- the letter "M" appears in the coffee pot reflection, an echo of the "M" by which Vermeer sometimes signed his paintings.
Could Manet be intimating that he was a painter of the same caliber as Vermeer? I vote yes -- an artist who compared himself to Titian would have no hesitation with comparision to another of the most famous painters, Vermeer!