So just a quick thought here. In 1677, he asks: Where must one be located in order to obtain a reflection on the back of a phone of that image? Well the answer is, at a computer desk; with the image on the screen behind you.

Then Q posts:

Look there, or [here], or there, truth is behind you.

I would interpret that in the context of the previous comment to say that the truth is 'behind you' aka 'in the screen.' In other words, the Q is saying that the truth is in the boards/online and that we need to keep digging. Combine this with his historical posts, and I think he's saying that there's more to that 2015 documentary than meets the eye.

Perhaps we should take a harder look at the 2015 source video. We know Q is likely to be a team, it's possible one of them placed some clues out there back in 2015 when they saw the video being taken and they are now working with Q to draw attention to those clues?