Maybe that finger is a 'wedding finger' in the US, but he's not steeped in American customs, is he? I never understood why anyone would assume an african elephant-hair ring, even though it's in gold, could be mistaken for a wedding ring. It just isn't a wedding ring.
I have no solution to the difference in clothing, other than it suggests he's not long arrived at the apartment or is dressed for leaving, which suggests to me that he was NOT living with Siddiqi and was the visitor, not the resident.
There was always an obvious need to create the Central Park fake, they wanted to show us two things; that he was there at the time and that he still had a relationship with the Dunhams. I doubt both. If that's him sitting in Bow Bridge with the Plaza Hotel in the background, then one might think they have posed him to fit between the Dunhams.
And that raises another problem. The growth of the trees on the shoreline indicate that photograph was taken some several decades ago. But all would be explained IF the pose was recent.
Seat someone in the desired pose with the lake and the hotel in the background, IN FRONT OF A STUDIO BACKDROP, place that body between the Dunhams on the bench, then add his head from a previous image. Now release both images and it looks like he was in Central Park that day, had his photograph taken on the bridge and then with the Dunhams...
So there you go, and you don't know who was sitting on that couch with Siddiqi, and we don't know who it was standing next to Genevieve Cook...or sitting in Central Park. Furthermore we don't know if it was him standing in the Street in Nairobi either.
But it's always the same jacket...