It is John’s habit to pull the door closed by the knocker, making it hang to the left. But notice that Sherlock’s practice is not to adjust the knocker to the left, but to the right. He’s annoyed to see that Mycroft has straightened it. To Sherlock’s mind, it should hang to the right if he is at home with John, or to the left, if John is out.
I love how Tom Hiddleston just stood like
This shot isn’t going to happen.
Thank God for that white shirt