Edit photo size in directory category listing

Please visit http://productwhorestore.com/wp-admin

login: test
pass: testacct (it's a subscriber acct, so it's all good.

Then go to:

I'd like for that tiny little thumbnail to be bigger, like much bigger. I got some help here getting the image on the individual listings to be bigger, if we could get these to be the same size that would be great. Thank you!