This book does go through song by song, every song in Swift's catalogue (up to and including TTPD.) It even includes some random songs not on her albums, like ones she wrote for film soundtracks.
The layout and presentation of the book are very nice. However, I would say that the actual write-ups for each song vary in quality and some are quite thin.
At times, there are quotes pulled from interviews with Swift, which are interesting. But when left to her own interpretation, the author doesn't really have anything to say beyond reiterating what is stated in the lyrics of the song. If you are the type of listener who pays attention to the lyrics, which I imagine many Swifties are, there won't be much here to surprise you.
I was especially disappointed by how little there was in regards to the songs on The Tortured Poets Department . . . which are lyrically dense works worthy of much meatier analysis than what is provided here.
I also feel the book missed out by not providing much commentary on the various literary allusions Swift puts into her work, or the way different songs link together.
The pictures are gorgeous though, lots of big full-page, full-colour, glossy photographs. ymmv on whether this offsets the shallowness of the text. Personally, I had a fun time looking through this book, but it's definitely an at-a-glance retrospective and not an in-depth exploration of Swift's work.