In Safari on iOS I notice that embedded Twitter images are not appearing on Facebook. Could it be Focus?

I can confirm it's Focus related, but the strange thing is that it doesn't block all Twitter embedded images. For me it blocked roughly half.

Javaun, is there a good component or other place to put these Disconnect blocklist bugs?

I'm adding this to the meta bug 1101005.

I put it blocking the Tracking Protection bug, which uses the same list. To update the list, we'd need to re-release Focus, since it doesn't use a service. But the list provider (Disconnect) would need to remove Twitter according to Policy reasons. Focus also doesn't have user-driven whitelisting to disable Focus for a site.

This is the offending entry: https://github.com/mozilla-services/shavar-prod-lists/blob/12e0ffbfb3bb02a038002cf638a0f2a0f5de03d6/disconnect-blacklist.json#L65