A Japanese internet meme originating from a quote from a feature on NEETs by the morning news TV program Tokudane!. The full quote is 「働いたら負けかなと思ってる」 ("I think that if you work, you lose"), shortened to 「働いたら負け」 ("you work, you lose").
This is one of the various slogans often featured on t-shirts worn by Futaba Anzu. To filter the large number of Anzu posts out, use the search you_work_you_lose -futaba_anzu.
Make sure this is what the shirt actually says before applying the tag to arbitrary Futaba Anzu posts!