WP e-cards – How to change default thumb size?

Hi, I am trying out WP e-Cards: wordpress.org/extend/plugins/wp-ecards/

The default thumbs are really really small. The size is not affected by defaults in WP Media, so thumb size must be coded somewhere in the php. I don’t know php. I did open it up and glance through it, hoping to see the numbers that represent height & width. No luck, no numbers.

Does anyone know how to change default size of thumbs in WP e-cards?

Thank you in advance.