Photon images not showing canonical URL

I’ve been reading that images served by Photon are supposed to include a canonical URL.

That’s correct. Jetpack’s Photon module, much like other good image CDNs out there, include a canonical URL, as recommended by search engines.

You can check this by querying one of your Photon images with cURL, like so:

$ curl -I https://i1.wp.com/edwardsturm.com/wp-content/uploads/2016/02/How-to-Make-a-Viral-Video-15-Simple-Ways-to-Harness-a-Viral-Trend.png
HTTP/1.1 200 OK
Server: nginx
Date: Tue, 12 Jul 2016 15:09:58 GMT
Content-Type: image/png
Content-Length: 1385220
Connection: keep-alive
Last-Modified: Tue, 12 Jul 2016 15:09:38 GMT
Expires: Fri, 13 Jul 2018 03:09:38 GMT
Cache-Control: public, max-age=63115200
Link: <https://edwardsturm.com/wp-content/uploads/2016/02/How-to-Make-a-Viral-Video-15-Simple-Ways-to-Harness-a-Viral-Trend.png>; rel="canonical"
X-Content-Type-Options: nosniff
ETag: "18c2a6e298505173"
X-Bytes-Saved: 843148
Vary: Accept
X-nc: HIT vie 20

As you can see, the canonical link is there.

This canonical link is common practice for Image CDNs; it’s implemented in KeyCDN as well as MaxCDN for example.

As recommended in those posts, as well as on this Moz community thread, you will also want to make sure your wp-content/ directory can be indexed by Google; having the canonical link redirecting search engines to the original images will be fairly useless otherwise.

I hope this helps.

I appreciate your time!

What sort of tests can I do to make sure my wp-content folder is being indexed?

Perhaps this is the reason my images are not indexing?

You’ll want to start by adding the necessary lines to your site’s robots.txt file, as suggested in the Moz community thread.

Then, you can use a tool like Google Webmaster Tools to submit your sitemaps to Google, and receive alerts and warnings when some of your content can’t be indexed.

I believe your images can already be indexed by Google, as some of them already were:
https://goo.gl/JvSpgF

Thanks. All the images currently being indexed aren’t on the Photon CDN.

There was a lot in the Moz thread so I’m not sure which information to follow. What should I add to the robots.txt file?

Thank you so much.

All the images currently being indexed aren’t on the Photon CDN.

They are. Take a look at the first image:
https://i.wpne.ws/ggDJ
It comes from this post:
https://edwardsturm.com/branding-critical-todays-economy/
The images in that post use Photon:
https://i.wpne.ws/gg8D

There was a lot in the Moz thread so I’m not sure which information to follow. What should I add to the robots.txt file?

You can follow the instructions posted at the link I posted earlier; this link leads you to the exact post you’re interested in:
https://moz.com/community/q/seo-dealing-with-a-cdn-on-a-site#reply_295329

I hope this clarifies things!

Thanks very much, I will do this.

Should I remove my attachments sitemap from the search console?

If you want Google to index your attachment pages, you can leave that sitemap there. That’s up to you! ??