I've had a problem with CF that I've contacted support about regarding images that CloudFlare has decided to add a "visibility:hidden" tag to. For what reason, I have no idea, but some people complain that images can't be seen, and when I look at the source, it looks like this.....
Code:
<img style="visibility:hidden;" data-cfsrc="http://imagehoster.com/image.jpg" /><noscript><img src=" http://imagehoster.com/image.jpg " /></noscript>
I don't know what CloudFlare app or service is doing this, but putting the site into development mode and hard refreshing, doesn't seem to fix it, because the visibility property is added to the post content in the message, it can't be removed by disabling CF. You have to edit the HTML source of the message posted.
After a lot of trial and error, the problem seems to be with the beta version of "Mirage: image resizing", on the CloudFlare settings -> Performance Settings tab. It just started happening a few days ago. I reported the bug to CF, and immediately turned it off for all my sites. I won't turn it on again. Strange how "pausing" CF didn't turn off this beta feature for me. Once I forced the feature off myself, my images automatically started working again.