I have looked on Android Firefox, Mac OSX Firefox, Android Chrome, Mac OSX Chrome, and flipped from portrait to landscape, I checked multiple instances, and thereby multiple themes (my account normally uses darkly-compact). In several of these scenarios the image is resized to be "tiny" as in <1/20th of the screen width, and from there it ranges up to 1/3rd, or at the absolute widest ~3/4ths of the screen (someone else also replied to the person you replied to showing this screenshot demonstrating that width for them too).
Throughout all of this, the person you replied to has only managed to conjure up 3 facts, one being an extremely generic term "web browser", 1 seemingly objectively false ("giant"), and the other 1 at best seems unreproducible by anyone here ("full screen width").
In short, the person you replied to seems to be acting in a trolling manner, as in like a canonical Karen, which frankly does seem surprising given how clearly articulated the original message of theirs was. We would be happy to help them diagnose further but at this point they just seem to be venting - granted though, not so much in the message you replied to on its own.
I doubt you can simply listen to someone online - maybe, but there's no accountability here and that seems like a hindrance. So maybe try to find an actual irl counselor? If you are part of any clubs like a religion then that often offers streamlined access.
I will offer one piece of direct advice though, not from myself as a good source but from someone who I have come to trust: maybe pause the dating scene. So many people try to rush into that, but if you haven't gotten yourself put together, then how are you going to offer to share your life with someone else? Depending on the circumstances ofc, like if someone was super awesome then they could help you, but it's a lot to put onto someone else, and isn't that a bit unfair to them? It seems kinder to both yourself to narrow your focus to getting your own life put together, and to others as well. If you are currently dating someone, note that I am not saying that you should immediately break up with them, it's just something to consider and make your own determination about what to do.