When you look at your twitter feed you usually see the authors profile picture to the left of their tweet (see image below). When their profile picture is facing away from their tweet it gives the impression that they want to be disassociated from their tweet and don't actually believe what they have written as they cannot bear to actually look at it.
If you look at the screenshot below I think you will agree that Jack Schofield and Livia Labate appear trustworthy, but Louis Rosenfeld and Christina Wodtke look very shifty to me.
Of the 142 accounts I follow 46% are companies or organisations that use logos, whilst the remaining 94 are people who use images of themselves (or a body double for Chris Locke).
Of these 94 people, 48 of them use photos that do not face left and 5 of them use cartoon avatars.
The 24 people who are using left leaning profile pictures need to change their profile pictures today as they come across as being untrustworthy and dishonest (according to my research).