The E-145 picture may be at such an lens/angle to make it appear more cramped than it really is. I’ve never been on a jungle jet, but I’m 6’3", and it LOOKS tight, although I’ve heard otherwise from several people who love them.
I dunno - looks like the left side of the 145 may lack headroom, while the right side looks okay. Like you say, it could be a perspective of the angle, but that guy with the gray hair in the lower left seems to just have a couple of inches.
For your specific case (hover the mouse over the various seating types to see what the evaluations were), I picked the generic 737-700 since you didn’t give a more specific sub-type. Here’s the ERJ
I had my own seat on an ERJ-145 from BTV-CLE i loved it because not sitting with someone leaning on me (which happened from CLE-MCO, some BIG guy slept the whole way it was a 737 luckly i had a window). But i would say the ERJ-145 it’s my favorite plane and it’s my size but i’m only 5ft 8in. But i would say your safe, my dad is 6ft and he had no problem at all, but he was on the right side.
I’m 6’ and have no problem with the erj’s headroom, in fact I like the way the fuselage curves to me, makes a good angle for me to lean against and get an hour’s worth of sleep. My dad’s 6’4" and he says it ain’t bad for him either, only problem is leg room when he has to put his bag under the seat.
Standing in the aisle though, I can push my head into the ceiling without stretching my spine too much. cuz it’s exactly 6’, I believe.
so yeah, if you’re 6’ and under it’s really a comfortable plane. over it might be pushing it, but not bad til you’re over 6’6" probably.
o, and as for those pics. the right side looks short because it’s the only side with overhead bins, so they stick out a bit causing the illusion. There’s no substantial height difference. But be cautioned that on the left side (seat A) there’s not much space under the seat to fit a bag. SO pack small or try to get a spot in the bin.