A photo like this needs careful balancing: the TV, the room, and the outside.
- First, as always, set the ambient exposure. Set your camera to match the outside.
- See how the TV works with that. If not good, find a good point in between, where the TV looks good, even if the outside is a little bright, like here.
- Keep your shutter speed below 1/250 sec or 1/200 sec, depending on your camera.
- Now add flash; add the right amount to match the ambient exposure. Bounce the flash from a point behind you that gives equal brightness through the room.
And that’s all. Not that difficult if you approach it right!