Unless the one across the room is a laser, it does matter.

Nits aren't a measure of total light though.

A 100 nits huge screen at a distance that covers 20% of my field of vision would be the same as a 100 nits tiny screen close to my eye that covers 20% of my field of vision.

Or to put it another way, things don't look dimmer just because they're further away. It's less total light because it covers less of my field of vision.

Fair point, I imagined nits was something like Lumen.

But I think it certainly matters, since nits indicate the amount of light (candles per square meter) hitting a board 1m from the source, if the board/eye is only 10mm away, the intensity in that spot is much higher.

That said, the area changes much more than the distance I think, so overal brightness is probably still not equivalent to 100 nits (at 1m).

> since nits indicate the amount of light (candles per square meter) hitting a board 1m from the source,

I think I can see how you've got here but that's not correct. It's about the light emitted per square meter of the source, not a measure of the light hitting a board some distance away.

Moving a screen closer doesn't make it more intense, because as you move closer it covers more of your vision. Total light increased, but not more intense.

I don't think the brightness changes with the distance. Take any screen (or any object). When you very the distance the color of it doesn't increase or decrease in intensity.

Are you saying that shining a laser from across the room is safer than from right in front of your eye?

I mean, yes. Depending on the lens, the laser will disperse its energy over a larger surface area.

Perhaps not materially so given the small relative difference.