Editing post foto to a vimeo video – is that possible?

Hello,
I know that you can′t really understand what I mean with the title, so I will explain that here. I′m a Filmmaker and would like to put instead of the post picture a video in german it is called “Beitragsbild”. As you will see, on my website you can only see that post picture and i would like to turn it into a video i have on vimeo.

you can see this on the following link:
https://www.bennorottonara.com/portfolio/salon-happy-hair/

The page I need help with: [log in to see the link]