Lurking Minicart for WooCommerce v1.3.0 has just been released. Minicart thumbnail sizes are now set in plugin settings, to fix WooCommerce 3.3 thumbnail size changes.
WooCommerce v3.3 introduced smart image sizes that can be customised by the active theme using filter hooks. This has allowed WooCommerce to become a little more theme aware, and it now looks better on more themes straight out of the box. But it has messed up image thumbnails in some cases, including in the Lurking Minicart.
To remedy this, Lurking Minicart for WooCommerce now has settings for the minicart thumbnail size. If you had set the product thumbnail size before updating WooCommerce, those values will be picked up and used for the minicart too until you use the new settings. Otherwise, they default to the pre-3.3 product thumbnail default size.
You can update to the latest version from your WordPress plugin admin page. Here’s the full Lurking Minicart for WooCommerce changelog.