How do I get my Emerson College film portfolio to upload at a higher quality??

I’m a hs senior and just submitted my app to Emerson a couple of days ago. They finally emailed me access to their portfolio page recently, but after I uploaded my film, even though I was using a decent wired connection, it shows up with much lower picture quality than what I had on my laptop’s video player. I rendered it as a 1080p .mkv which is supported according to their site. It looks like I can still resubmit my portfolio and Emerson’s website doesn’t give a hard deadline for their portfolio submissions, so if anyone could help me out with this soon I’d greatly appreciate it. To clarify, the film is still ‘watchable’. There are no other issues with it besides what I’ve stated here, but obviously getting it to look prettier wouldn’t hurt my chances of getting admitted.

Thank you

(This is my first time posting on this site so sorry if I did it wrong or I’m in the wrong section or something)

I get that you want your film to look as good as possible. But, as long as it looks decent, I wouldn’t be too concerned. The video quality is probably far less important than if you conveyed to them the ability or talent to tell a visual story.

Yeah, that makes sense. Thank you for your response.