title: CloudWatch synthetic monitor screenshots appear broken in management console
body: <p>I have a few CloudWatch canaries running, yesterday I could view their saved screenshots in the CloudWatch Management Console, but today all screenshots are rendered with a broken image icon. 
  This is in the CloudWatch->Canaries->[canary name] page of the console.</p>
  
  <p>I see today that the web requests for the PNG images come back with a Content-type: text/html 
  That explains the broken image icon. Don't know what the content-type was yesterday, but something has changed. The images are actually coming back, I can wget them by URL and view them on my local.</p>
  
  <p>I'm just trying to write documentation for users who will use the CloudWatch management console to check on canaries. I'd like to direct them to the console and allow them to do what I did yesterday: conveniently click and browse screenshots.</p>
  
  <p>Has anyone run into this before? Any ideas on how I can get the images to appear again?</p>