Sry if this does not only occur in UE5
I was trying to add a video (MediaTexture) as a brush to my image, but I can’t. I started researching and saw people commenting about drag and drop your MediaTexture asset directly into the Blueprint Widget, so I decided to give it a go and boom, it works fine, lol. But this step automatically creates an image with my MediaTexture as my image brush, so why can’t I add it manually, but when I drag and drop it, the editor creates it for me?
I have a video demonstrating here:
And I saw this inside unreal source code (File: Engine\Source\Runtime\SlateCore\Public\Styling\SlateBrush.h):
And yep, I tested it with a fortnite dance video 
So, is this behavior intentional?