The real trademark of a Def Leppard single is that it had a basis in hard rock, which means some strong guitars, but is very melodic, and has a good riff. There's also the backing vocals, used in a very non-metal way... they are soft, almost like an echo of the Joe Elliot's lead.
Def Leppard used several guitarists in their performances. Here, Steve Clark and Phil Collen took lead, with Rick Savage on bass, and Pete Willis on rhythm guitars. Rick Allen was about the only one not to use a guitar. He, of course, was a very talented drummer. This all gave them a very layered, unique sound that was hard, but at the same time showed a pop sensibility.
The album hit number two, mostly on the strength of "Photograph", but "Rock of Ages" also charted, and to a lesser extent "Foolin'" and "Too Late For Love" got some attention. But the album, thirty five years later, is perhaps a victim of the lead single. There is a bup drop off after "Photograph"; the rest of the album is just not as good. Plus, it was really the following album, "Hysteria", that really shot them into another stratosphere, so the comparison hurts this album.
While this isn't their best, it is a part of their development, and there is done good stuff here. If you like any of Def Leppard's music, this is certainly worth giving a listen. It holds up better than most hair metal of the 80's.