EFFECTIVE USE OF CDN

Hi,
I just updated my WP theme and ran a test and found an X for Effective Use of CDN.
I didn’t change any setting.
The plugin used is W3 Total Cache. I cleared plugin cache before testing.
Here are the test results :
https://www.webpagetest.org/result/160807_YP_2BA/

Anything I can do to make good? I got an OK mark for Effective Use of CDN before I updated the theme.

Do you have a CDN that you are using (cloudflare, etc)? Is the CDN on a separate sub-domain?

Yes, I am using MaxCDN. But not sure if its on sub-domain. I did not set it up with sub-domain.

Looks like 96b1ada84e3baac616429bf8.lejgz897bo7stx.netdna-cdn.com is your CDN domain and several images are being served from there but a lot also are not (which are what got flagged).

Hi Patrick,
https://www.webpagetest.org/pageimages.php?test=160808_29_XE8&run=1&cached=0
The images that are displayed in the above page are all the images in my landing page.
The links without attached image are not images that I have loaded. They only showed up after I updated the theme. They were not there in earlier tests.
I tried to open them but they didn’t open.
Where could they come from and what to do with them?