Not safe for work (It's not a NSFW-ish question, obviously...)
I already know that 'NSFW' means, "Not Safe For Work."
But, I can't fully understand the whole meaning of the phrase.
Does it mean that it is lacking the productivity while working?
or does it mean that it is dangerous to watch the content at your workplace because it is possible that other workers would accidentally run into you while you are watching it and misunderstand your behavior or something?...
Please answer me if you have any idea of it. Thank you very much. ^^