Completed

'#105955 Activity story stream comments use wrong content type id when configuring the editor' has been completed for 3/2018 - March Service Pack.

Reply to QuickPost with an image

Believe it or not, you cannot reply to a Quickpost with an image. In the modern sharing world that is not a default behavior. Vote to restore (yes restore, it was stripped from the editor) the Quick Post Reply with Image.