@Jairus That's correct. Once you've made sure that your posts include Open Graph meta tags, and if the images added in the meta tags are large enough, there isn't much more you can do, but trust that Facebook will take this into consideration when building post previews.
The image meta tags seem correct on your site, so I'm afraid there isn't much more I can do to help here.
@samaralife Thanks for all these details.
You're not using any plugin to handle Open Graph meta tags, so everything on your site is handled by Jetpack. Here is what Jetpack looks for when building Open Graph Meta tags:
1) If you've selected a featured Image, it will be used as an Open Graph meta tag.
2) If you included a slideshow into your post, we'll pick an image from there
3) If you don't have a slideshow, we'll look for a gallery
4) We will then look for other images attached to your post
5) If you use an image that's not hosted on your site, we'll use it
6) Finally, if you didn't use any of these images, Jetpack won't add any image meta tag to your site.
In these 4 posts, you had inserted images (either through a Featured Image or in the post itself). The Jetpack Open Graph meta tags were built properly, as you can check by viewing the source code for each page, or by entering the post URLs in Facebook'd debugger:
Yet, Facebook chose to ignore these meta tags when building the post previews, and even ignored the title tag in your fifth example. As I mentioned to @Jairus earlier I'm afraid there isn't much you can do here, with Jetpack or any other Open Graph plugin; it's up to Facebook to use these tags or not.
2. When there is no picture in the post
Since there wasn't any image in the post, Jetpack didn't create any image meta tag, and Facebook then decided to pick an image at random to build the post preview:
If you want to avoid this problem, you could add a default fallback image that would get added to the Open Graph Meta tags when Jetpack can't find any image in your posts. You can follow the instructions here to learn how to do this:
I've just seen the info about possible FB pic size requirements. But in most of my cases the pics are inserted into the post and are 700px by the longer side.
Since you use Jetpack to manage Open Graph meta tags in your posts, you do not have to worry about size requirements; Jetpack does it for you, and won't add an image as a Open Graph meta tag if it's too small.
Thanks for the heads up about the WordPress SEO. I have disabled that feature and now only have the JetPack Share feature turned on. (I hope anyway).
As long as the plugin is active, Jetpack will not output any Open Graph meta tags. I would consequently recommend that you turn the OG meta tags back on under SEO > Social in your dashboard.
This was working until about a month ago. Anyone have a suggestion to replace Jetpack Post Sharing?
As I mentioned above, while your Open Graph meta tags may not have changed, it seems that Facebook doesn't always use them to build the post previews. Unfortunately, there is not much we can do on our end, apart from mentioning the bug to the Facebook developers.