I see. It's an ethnic joke. I would try not to assume hackbinary was being racist even if I picked up that possible meaning.
But basically, the joke is that Mañana never comes. Anyone familiar with (remote) Island life, from Islay on the west coast of Scotland to Saltspring Island on the west coast of BC will surely identify.
Many countries view hard workers working through the daylight and having evenings / night to themselves. However in the hotter nations the middle of the day and afternoon is often taken off, and work restarts later going into the evening/night. Thus it often appears like these countries only work half days.
The truth is now common knowledge around Europe however the traditional image of a Spaniard asleep in the middle of the day persists alongside the camp French snob and the Tea Toting and Tutting Brit.
As I see it the joke is no more racist than joking that the US brings kilotons of freedom to the world or that Canadians are sorry.