Can I select a variant to show instead of the default variant?

The app will display the first variant by default and this behaviour can not be changed.

However, the app shows a built-in variant selector to allow your visitors changing the variant that fit their needs before adding the product to the shopping cart.

Please note that you can change your default variant on your Shopify admin, just go to the variant editing page:

and click on the 'Reorder variants' option: