That picture was taken and sent to the tint shop previously for one specific reason - to show how much of a gap there was between the edge of the tint film and the edge of the window - that's why it's like it is. I just posted it here to help illustrate how much of a gap there was.
It seems that this tint shop being in business for over 30 years may actually be a "con" in this case - as they are still tinting like they did 30 years ago (manually cutting the film instead of using computer-assisted methods, etc).

I've honestly never even heard of tint shops using a computer to cut the film, but it makes sense.
Sure enough, after I started looking around, I found another local tint shop that
does use a "plotter" to cut the film - and they've also won the "best as" award for local tint shops for multiple years in a row now.
I had my other car tinted at the same shop as my Challenger and they did a great job - and after ~3 years (maybe more), the tint still looks as good as the day it was applied, which is why I chose to go to them again. I also wanted 3M tint (lifetime nationwide warranty, etc). They are actually a very highly-rated, 3M-authorized tint shop - but it sounds like they should probably update their equipment and stop relying on people to manually cut the film, like they did 30+ years ago when they opened.
Oh well, live and learn - I'll go back on Wednesday and give them a chance to fix the issues. Probably won't be going there again for future vehicles though.