Feed images don't load

I have one feed where images for some posts do not load. I can’t seem to figure out why those posts show broken images while others work. If I go to the post’s website, the images show correctly, so I’m wondering if it’s related to the way Newsblur loads the image URLs.

An example:

The post website: Miss Cellania: Cucumber

Image URL: https://4.bp.blogspot.com/-Aa4MUSVOSJs/VbRdq_YAMDI/AAAAAAAA28c/K5Fqicay-fs/s1600/cucumber_fark.jpg