Hello,
Maybe I did not understand what exactly you want to implement. Do you mean that you want to hide the product gallery that you added here https://gyazo.com/7638ffe86d226a1c4c54bef0cbe06c7c once you choose the variations? And show only featured image of the variation https://gyazo.com/963c9865fe31f60fcca70fe55429eb28 ?
Regards