[brian-armstrong]

It is not against code to hide low voltage signal cables behind the wall. It's only against code for mains voltage. And there are good reasons for it. Just because you showed up to this conversation not knowing what they are doesn't mean they don't exist.

[Nevermark]

1) I was the person who suggested hiding the cords.

2) Zooming into the picture of the hanging digital picture, those looks like fat highly insulated consumer cables to me.

[Galanwe]

I think he suggested hiding the power cable of the screen (so probably USB at 5v), not bringing a power cord up the wall.