OK, I’ve been getting up to speed on RSS feeds and Facebook interaction this afternoon! ??
It looks like Customizr does nothing to change the standard WordPress rss feed. And the standard WordPress feed doesn’t have images in it. (If you go to britican.me/feed, you can see the feed that is generated.)
There is some standard code that you can find on the web (such as this) that will append a featured image to your feed. But there is no guarantee that an RSS reader will use it.
I checked out Feedly (a very popular RSS reader) and on your site it seems to be picking up the second image on each post (or the first, if there is only one).
twitterfeed seems to suffer from the same problem, as can be seen here.
The key to all of this behaviour lies with the documentation / posts associated with the Facebook plugin, which is partly written by Facebook and partly by Autommattic (the company behind WordPress.com). There are two key pieces of info:
– The plugin explains that it uses the Open Graph protocol “[to optimize] your content for social sharing and rich story previews on Facebook, Twitter, Google+, Mixi, and more“. WordPress itself makes your images available via that protocol in the source of your pages. In this page on your site, for example, there are several images and they are shown in the page source with <meta property="og:image" ... tags.
– This post, which started a week ago (when you started having problems) gives more clues. Specifically, one of the authors says:
Facebook looks for up to three images on each page to share. If someone copy-and-pastes a URL into a Facebook status composer they can select one of up to three images. An unattended share uses the first eligible image.
Facebook builds a list of images by looking at the images provided through og:image markup as well as <img> elements on the page. Facebook may skip over an image if it is not a good choice for social sharing: a 50×50 image may be thrown out while Facebook’s parsers keep looking for an image.
Providing more than one og:image helps provide more options if the first image is considered ineligible by Facebook or someone sharing your URL decides image #2 or #3 better represents the piece of the story they would like to share.
In plain terms, this says that Facebook will basically decide which image to use and you cannot influence it.
Having said all that, on a page such as the one you mention, which currently has no images at all, you would do well to set a featured image. In that way, WordPress will at least give Facebook one image to use.
Whether it chooses to use it is another matter.
