I think the easiest way is to export a movie to a USB and play it from there using the TV (check if the TV plays movies from USB first, because some old one only displayed pictures and music, but no video. All the information and codec supported are in the TV manual).
If it's a short video, I always prefer to duplicate the edit many times in the same timeline and deliver a long movie than a very short one to avoid problems with the tv stoping or the lack of a loop feature.
canelson wrote: ...
If it's a short video, I always prefer to duplicate the edit many times in the same timeline ...
Excellent suggestion, my - little, 3 devices - experience with smartTVs is, they show some HUD/overlay on loop beginning, which is a bit distracting when seen every 90sec (or wotever program length).
Check supported specs, although 2016, often just fat32 is allowed = 4GB max file size, naming scheme 8+3 ....
Speaking of HUD: in my case, they displayed the mp4 name - so don't call it "boring v2", "clientsheaven", "wtf_666"
Either cable tie as suggested or using a good industrial Velcro is also an acceptable solution. I would choose a method that allows the device to be easily removed if needed (i.e avoid double stick tape and the like).
Never heard of the Sumvision so did some research, Seems there's a version 4 now. Looks like a cool little product.
Be careful that your client doesn't get all excited about video and suddenly decide that they want a pet image to span the sets or to display the movies vertical. At that point, you want to investigate digital signage applications and hardware.