[Gradient-Ascent]

> still had a hand written note taped to the side of it, something to the effect of "Please don't turn this computer off."

You sound like "nobody has cleaned this piece of paper off [yet]" or "will be cleaned of soon". But it is the central piece of the exhibit, very intentionally. Probably written by TBL himself and illustrating a feature of the new invention: "The internet is always on"

And I heard of this before, that TBL developed the WWW on a (NEXT-)workstation, which also was the first www-server with a sticker on it that said "This machine is a server. DO NOT POWER DOWN!" (https://commons.m.wikimedia.org/wiki/File:This_Machine_is_a_...)