WP Smush image compressing - gtmetrix showing 0 score for image optimization

I installed the WP Smush plugin and have losslessly compressed all the images on my site, of which there are 5200 right now. The plugin tells me that all images have been compressed. However, when I run my gtmetrix report, it's giving me a 0 score for optimizing images. I've pasted the link to the gtmetrix report below. There are 2 types of images I'm seeing in the report: (1) regular recipe photos which seems really strange because I would have thought he plugin should optimize these automatically, and (2) images relating to my theme that are NOT found in my media library. Assuming the WP Smush plugin can't access those images, how the heck do I compress them?

Thanks for the help