Why it’s harder to forge a SHA-1 certificate than to find a SHA-1 collision
  $ curl -s https://blog.cloudflare.com/content/images/2015/08/white.jpg | md5
  ccf22bc377846166ed65cd3cd58d2e3d
  $ curl -s https://blog.cloudflare.com/content/images/2015/08/brown.jpg | md5
  810cac197d97da7b216c7883be523495
  $ curl -s https://blog.cloudflare.com/content/images/2015/08/black.jpg | md5
  6bede506abffe08d0c2406d92fbff393

Let me guess, the CloudFlare CDN is recompressing the images? :D