This is already possible (see below 
) but currently the implementation is that you have to explicitly choose which image to show. There is (currently) no feature in cards that implicitly and automatically chooses image for you.
Related feature request:
() How to show media preview in bases:
The problem currently is that this image property supports only limited file types (no mp4 or pdf support for example). The above FR talks about pdf but similarly we would expect to get mp4 support.
https://help.obsidian.md/bases/views#Cards