Whenever you try to post a link to a profile (https://twitter.com/[USERNAME]/) Facebook goes on and fetches the Open Graph-Tags (http://ogp.me) provided by Twitter and build the little url-preview-box.
Unfortunately Twitter responds with multiple objects in the og:image tag, so Facebook often uses the wrong profile thumbnail for an account. Although you can circle through the available images when posting, sometimes the real profile pic doesn’t even get displayed. So it is, for example, with https://twitter.com/skbozen/.
See Facebook Object Debugger:
Saying “Inferred Property: The ‘og:image’ property should be explicitly provided, even if a value can be inferred from other tags.”.
What this results in is choosing Facebook the profile pic of @johk95 instead of @skbozen (skbozen retweeted some tweets of johk95 time ago)…
This really disturbs and I hope Twitter engineers can do something about that…