Facebook chat's capability to display pictures in place of [[xxx]] has been on vacation but it's finally back!
Here's a quick crash course:
1) Try your username in between [[ ]] in chat
2) Now try a page's username such as [[ragecomic.web]]
3) Or try its ID []
Just think of the possibilities. Have fun with meme-rich conversations!
Chrome extension: https://chrome.google.com/webstore/detail/cblicmfimjjnpnpkbbfflojmdkebmmao/related