These settings affect the actual dimensions of your product images in the shop pages.
You can skip this step in case you're starting a new website and your WordPress installation is fresh, but if you're switching from another theme and you already have products in your store, you need to make sure the WooCommerce image sizes are the correct ones for your newly installed theme.
1. Navigate to WooCommerce > Settings > Products > Display and find the "Image Options" section at the bottom of the page. Update those values with the following ones:
Catalog Images: Width = 190, Height = 243
Single Product Image: Width = 510, Height = 652
Product Thumbnails: Width = 114, Height = 145
2. To see the changes after you update the image sizes, you need to re-generate the images WordPress is using in your site. You can find the option to do it by navigating to Tools → Regen.Thumbnails.
Here you can find the plugin in case it's not installed or you haven't done this before.