Hello,
Nope, catalog images that are used for these 2 items (and some other items) are different.
Compare
https://vinopura.nl/wp-content/uploads/2017/11/101042-300×300.png
https://vinopura.nl/wp-content/uploads/2017/11/102107-Maupas_Gamay-pinot-noir.png
1) Go to WooCommerce > Settings > Products > Display > set the necessary image settings for the catalog images. You can read more here https://docs.woocommerce.com/document/fixing-blurry-product-images/
2) Install and activate Regenerate thumbnails plugin and regenerate all the thumbnails (Tools > Regenerate thumbnails)
3) Check your grid after that.
Regards