rambling more on this (sorry!)
background: my previous transfem jay meta but specifically the doylist perspective section, jay feels the need to get rude and one up people to have any sort of power, and in general places a lot of his self worth in other people/matt, i use masculine and masculinity as very loaded terms here and just know that even when i don't write them i'm always saying them with quotes
in the blindside coolness is very gendered. yes that's as a result of the show itself centering around men and typically masculine interests, but i think its really clear here specifically. jay feels emasculated at the start of the episode and the way to fix that is by dressing up as a traditionally masculine character. it's really interesting to me that jay's perception of coolness is through the lens of media (likely thing for ntb to do, obviously.) but, more specifically, more nerdy, childish, and, well, "uncool" ventures. it's not really anything about their characters thats cool or uncool, it's the stuff they're Into that's making them that way. the way he thinks they can come across as classy and cool is by doing a star wars show, that's like... THE stereotypical nerd interest.
allow me this tangent: it reminds me a lot of how this stuff is handled in gamer webcomics and media. having nerdy/unmanly interests is a really common punchline in them. these characters being weak or not traditionally masculine is funny, but there's a lot more empathy in those types of jokes. they're written with the understanding that you (yes you) have also been cast as not traditionally masculine, so it's a sort of reclamation of that. this is a lot more empathy than is afforded for punchlines involving gay people, women, or trans people (for example) in these same comics, even if they're also ostracized in the patriarchy. they're more clearly an other that you can put down to in turn reaffirm your position on the ladder so to speak.
which of course is partly why jay engaging with masculinity has to involve getting one over on matt by stealing his costume AND dressing him up in something embarrassing. he has to reaffirm his own masculinity by in turn reaffirming how unmanly matt is. their gender presentation as literal costumes and jay gets to put matt in something foppish to make himself look better by comparison. this is, like, one of the only times jay hits on a girl in viceland. "i couldn't let you ruin this awesome costume by being blind and uncool!"
the thing that always gets me about the blindside is that, in the fight scene, jay doesn't do anything. it's funny, obviously, but oh my god. he stands around waiting for matt to protect him and winces from any violence, he tries to pacify matt/the fight at points (he asks one of the men if they're ok after matt hits him, he breaks up the fight when cops pass by). he's a damsel in distress, that's the archetype. he doesn't even get to reclaim the devil sticks!! that's killing me, in any other sitcom or cartoon or whatever the arc would be that something jay enjoys actually did come in handy (to beat the shit out of a bunch of dudes but still), and to a literal extent it did, but jay is not allowed to be the one to prove that. matt is, matt's the one to prove all of their nerdy and uncool interests are useful and worth keeping around by using them to beat the shit out of a bunch of guys (even the way he engages with violence to begin with his, well, one to prove himself as cool, but two with the help of those uncool interests (daredevil, fighting games). matt's the one that gets a costume in time for the thing at all, even with the masculinity as a literal costume read, matt is still able to attain the costume in the first place. you're allowed to be a failed man as long as you still, on some level, engage in/with masculinity (in this case violence, but more broadly, as another example, putting down others you deem acceptable to put down). that's just not something jay is not allowed (or able?) to do in this circumstance, for some reason.
(and this is after a whole episode of matt trying to slot jay into a caretaker role. you have to dress him, you have to lead him around. and in the end jay acquiesces to that and stays by his bedside)
and in general (IN VICELAND!! and movie) jay isn't particularly physically violent. matt starts the fight in the buffet, the shooting at the end of the bank is staged (bc of matt's idea, and in general matt is way more physical with jay/the world at large, even non-aggressively). the only other example i can think of is shooting luke as famous jay which aaaaaa
famous jay is already more masc than regular jay comes across, and he's supposed to be a bad end, it's supposed to be wrong to us as an audience
the shooting only happens after failing to come across as charming and likeable, as a way to win back the band's favor
it's contrasted with matt shooting the toy gun at jay. jay isn't even the one to fire the toy gun in that first scene! he's presumably never the one to fire the gun! jay isn't able to even engage with pseudo-masculinity like matt is for some reason. until this scene where he actually expresses a desire to and it's an unmitigated failure (partly because it's an extension of QUOTE UNQUOTE real masculinity that he's unprepared to take on.
i still standby a lot of what i said in my original big huge post but the bit about jay not really feeling like he's being emasculated by the show (at least in the way a lot of other characters in different shows would be) is something i have a lot more nuance towards. mainly being that the show just has a lot more empathy for jay In General in spite of how mean spirited and embarrassing it all can get, and part of this empathy comes from the fact that jay is, well, still an "actual" man at the end of the day.
really not much else to say about it other than the themes of misogyny intentional or not love running deep in all art men make, even if it's stupid nerdy bullshit.