Help w\ oversized Woocommerce Featured Image

Hello,

We’re in the process of setting up a woocommerce shop page, but the default featured image size is too large for books. Uploading smaller images results in the image being blown up to fill the space.

We’d like to have 200×325, but can’t figure out a way to set that up. Would you assist in showing us how to reduce the featured image size?

For reference, the page is at OldSchoolDnd.com/loot.