HOLY SHIT, THE FUCKING CAMERA.

YOU. GUYS. I APOLOGIZE FOR THE AWFUL SCREENCAPS WITH THE LITTLE TIME BAR AT THE BOTTOM, BUT I JUST. NEED EVERYONE TO SEE THIS AND COULD NOT BE FUCKED TO FIGURE OUT A WAY AROUND IT, SUE ME.

So: Sherlock finds the camera in 221B, right? And then he’s on John’s laptop (I assume that’s John’s laptop, anyway, since it’s John with the Mac, isn’t it? Sherlock’s got that little black netbook-looking dealie, and hell, even if it’s Sherlock’s laptop the point still stands) and he pulls up the feed of himself:

And then, then the shot focus changes and holds, sharply, on the camera in Sherlock’s fingers:

And that’s the kind of focus switch that would be…dramatic, right, would make a point, except it’s not like there’s anything dramatic about the reveal that the camera works, that they’re being watched, that’s already been made exceedingly clear. The only point in this moment of emphasis would be if it paid off later in the episode–which, obviously, it doesn’t–or if it’s something Sherlock’s focused on, really, really thinking about.

And then he sets to typing away, keeping a careful eye on how far away John is:

And, in fact, only fully focuses on the screen once he’s positive John’s going to stay exactly where he is, when he’s sure John isn’t going to walk around:

AND THE THING THAT STOPS HIM TYPING IS WHEN HE THINKS, IF ONLY FOR A MINUTE, THAT JOHN DOESN’T BELIEVE IN HIM:

And once he is assured otherwise, he looks back to the screen as he double-checks that conviction (“100% ?”):

Now, we’re talking about Sherlock Holmes here, people. We’ve been introduced, more than once, to the way he feels about sentiment, to the way he feels about public perception. Of course the relationship between himself and John Watson runs far deeper than either one of them seems to enjoy admitting, but despite that–can you imagine Sherlock Holmes pausing in what he was doing to test John’s faith? If it was something for the case, if it was something that was actually going to lead him closer to beating Moriarty, and with the firm knowledge that he’s pressed for time, that the police are coming back–can you honestly imagine him stopping to have that conversation right at that moment?

No. No. The only thing that would stop him, in that situation, is if he was doing something for John, or about John, or dependent on John, and was hit with the sudden realization that it might be futile. That John might not believe in him enough for it to be worth it, or enough for it to work.

SHERLOCK HOLMES REROUTED THE SIGNAL FROM A WIRELESS CAMERA SMALL ENOUGH TO HIDE ANYWHERE TO JOHN WATSON’S LAPTOP, AND THEN HE PUT IT IN HIS POCKET AND TOOK IT WITH HIM. THAT IS WHAT HAPPENED. YOU CANNOT CONVINCE ME OTHERWISE.

ETA: ADDENDUM HERE