I have not found a way to have video’s be setup for “mobile”, they are all set up for Youtube. You should create a vimeo layout that auto selects the center for mobile video’s so there is no black space on the left and right side. Shaped more like the TikTok feed. Then we can leverage testimonials from Instagram stories, TikTok, and mobile reviews. It really looks bad with all the black space, but everyone is submitting video reviews on mobile phones and there is no way to present them nicely and maximize site space.
Folks, our former Wishlist portal, where our users shared their requests and suggestions, was transferred to this forum. You’re most welcome to vote, add new ideas, and leave your comments here — we surely will consider them all! 
Original Votes: 2
There is a lot of people taking shots on vertical on their phones, Vimeo gallery on Elfsight shows a black margin in vertical videos and it looks a bit weird.