One of those dread motivational posters of the past.
Some of these posters, while all a little cheesy, have good advice. This one doesn't, however. It's universally agreed by industrial psychologist that employers and employers are better off taking their time off. Paradoxically, Americans are terrible at actually taking their time off, and most Americans do not take off all of the time they're entitled to during a year.
I'm one of the worst offenders. In a typical year, I don't take a real vacation and I probably work at least half the Saturdays in a year.
On this poster, it's important to keep in mind that Saturday as a day off was a recent achievement for labor, so it wasn't fully accepted at the time.