portfolio feature images not the same sizes

This is so ridiculous, but my OCD is going crazy trying to figure out why from my portfolio page or home page, some “featured images” are different sizes.

http://planningforever.com/portfolio/

I swear: I have checked and double checked. They are all the same width/height original. They have the same slideshow image size (Entry without Sidebar), There are no caption titles or caption texts.

I cannot figure out why most of the featured photos are larger and a few are smaller. For instance: Amanda Wade, Kerry Devine, Lisa Miller, and more are smaller. Please help?