It’s also worth noting that camera angles and especially lens distortion have a tremendous impact on how a helmet (or person or anything really) looks on screen.
Case in point:
These are both me in the same helmet on the same day. Photos taken within seconds of each other. (I zoomed and cropped just to focus on the helmet, but I didn’t manipulate the vertical or horizontal stretch. This is exactly how the photos appeared when taken).
That’s really interesting to see the different effects, and I see what you mean. (Also, rocking that helmet. You’re making me want one!)
I still think they possibly have altered the helmet though because it feels like it’s longer to me in - I think - every shot we’ve seen him in so far, in the trailers. I can complain about it in a nitpicky Star Wars nerd way and still prefer the original more boxy version, but ultimately they probably changed it as Tem Morrison found the helmet too uncomfortable when filming Mando s2 (and he’ll have been filming long days in an already uncomfortable costume). And that does come first. It reminds me of how I don’t like the live action Ahsoka look, with much shorter head tails, but that’s also a necessary adjustment for Rosario Dawson when she’s doing stunts etc.