Because it's a highly notable building in the heart of Nashville known to be called "Music City" leaning more towards country music.
Edit: oops thought you were asking why Hardy used it.
Why would At&t... Not sure, but Sauron did have vast coverage in middle earth.
But it wasn't At&t that built it, they bought the company before them.
When I moved to Tennessee people told me it was the batman building
Usually those water resistant seals are just a tiny bit of adhesive gunk like so (looks better before removal obviously). Eventually it may just break down. Also it isn't waterproof, so holes like the charging port, speaker, microphone, stylus, you don't want submerged for long. Might do better flipped upside down, but there is usually a speaker and mic at the top as well.