This is a bit odd. From my feddit.uk account (this one) I get the above for posts on !dailybunnies@lemmings.world.
If I log into the account they were posted with (this is my bot) on lemmings.world they display as expected:
If I log back in as myself on feddit.uk website, the images also display as expected (Connect doesn't seem to want to upload this one, but you'll see it without logging in at feddit.uk/c/dailybunnies@lemmings.world).
What's different?
I'm not sure what might be causing this but I am seeing the image correctly (at least from lemmy.ca).
Thanks for checking. It's very odd. I had a quick look through the API and it's showing correctly as image/jpeg. Obviously I don't know how Connect determines whether to show an embed or a link so this might not be relevant.
btw, I just discovered that Connect is now available on the share list, and pre-fills the title and body. That'll make posting articles much easier - thanks!