Customizing featured image & text width

Any ideas on how to customize the featured image size and text width size on the Contango homepage? I updated the custom image size dimensions in Functions.php (changing it from 200×180 to 150×150) but it didn’t seem to work. I’d like to make the image smaller (and hard crop to square) and then expand the text to the left. My site is here: http://lizdoes.com

Any suggestions are appreciated.