Hello,

We just checked one more time with the Storefront theme it also loads large image on mobile https://monosnap.com/file/eYCDNgzODtNA3F6ua6X1buYQOxHCWp
And here is a screenshot with WoodMart https://monosnap.com/file/C5Tl9uzMBFKoyIs77aS8T2qCf1kjl4
We tested on this page https://woocommerce-477426-1641986.cloudwaysapps.com/categorie/noeud-papillon/
Please, let me know if you test it differently and specify the exact product where we can check it also.

Kind Regards