Looking at the two pictures submitted, I'd say he's the one in the suspenders in the older picture, and nattily dressed in the vest, befitting the more upscale nature of the establishment, in the second picture 24 years later. Amazingly, he's is taking the same stance and seems to be in the same position in both pictures.

Zoglmann’s, as a saloon (circa. 1910), then as a restaurant (1934). From the Heinz History Center blog .

The original church building in the photo is still there today, minus the upper portion of its tower. The apparently more elaborate St. John the Baptist Ukrainian Catholic Church is just a block away. Wonder if there's a connection.

A 1910 directory lists Wolfgang Zoglmann as a saloon keeper operating at 601 Carson Street. He was born in 1875 in Austria, and had five children with his wife Mary before he died in 1949.

The Carson Street Freight Station is in South Side Flats. Homestead is too far to the southeast and around a couple of bends in the Monongahela River to have a view of downtown Pittsburgh.

hasn't changed much in 80-plus years. Now a smoke / vaping shop.