There are several things going on there. The largest building on the far right is now filled with artist studios. I believe it was originally associated with the Reading Railroad, but I'm not 100% on that one. The big metal square in front of the building is part of the Reading Viaduct structure, itself. This is an abandoned section of passenger rail that is may one day be an urban park. You can also see an abandoned rail station, nearer the center of the shot. Without knowing what you are looking at, it would be easy to assume the two buildings are one in the same, but they are technically two buildings.