Just in case this bites anyone else in the future and reads this, the popular Adblock Plus extension auto filters images based on their urls via this list that’s enabled by default: https://easylist-downloads.adblockplus.org/easylist.txt
Turns out, Eddie’s 300x250 pixel thumbnails happen to be the same dimensions as a widely used ad unit size and Cargo is putting those dimensions in the url.
To avoid this bug, stay away from these thumbnail sizes: 120x60, 120x600, 160x600, 300x250, 468x60, 480x60, and 728x90