The image that started it all: "No safety. Smoking first." (plus introduction to community)
(i.imgur.com)
Welcome everyone! I created this community after coming across an example in !funnysigns@lemmy.world
In a "NoSafetySmokingFirst", the text reads correctly left to right, but visual cues (like colouration, vertical proximity, or horizontal separation) lead you to try to read it top to bottom.
This is similar to, but distinct from, the more widely known "DontDeadOpenInside" format. In that case, the text reads correctly top to bottom, but visual cues (like colouration, horizontal proximity, or vertical separation) lead you to try to read it left to right.
That's pretty much all you need to know! Hope you enjoy yourself here!
*Edited to improve explanation and add examples.