Optional Cloudflare Performance features may potentially cause issues with images or pictures on your site. The two features that may cause issues are Rocket Loader or Mirage.
So you should try turning them off in your Speed Settings if you see an issue.
Tips:
– Rocket Loader would generally impact images that are being delivered by something involving JavaScript or jQuery.
– Mirage Lazy Loader is generally the cause if the behavior is only happening in certain browsers. Mirage is only included for domains on a paid Cloudflare plan.
So you can rule this feature out if your domain is on a free plan.