Thumbnail missing in mobile WooCommerce-Cart

Dear GP-Crew,

i've got a little issue with GP and WooCommerce: In cart, there should be a product-thumbnail next to the "X" on mobile devices- but the thumbnail shows only on desktop browsers.

https://www.zehnideen.de/warenkorb/

I've tried all the settings but i cant find a solution.

Thanks in advance for any hint.

Regards,
Lars