"An architect a designer is.A designer an architect is not."
While I thought I understood it at first, it really took some time plus spending more time with both to really understand the difference. From what I have observed (and practiced myself), designers are really focused on form plus function whereas architects are focused on intended use and managing complexity. That's what I have found to be different about the two roles.
The photo is of a Washington, DC Metro station, perhaps the Union Station stop if I recall correctly.