This tests tracking across the printer in all directions. Is good at finding axis problems as well as un-level surfaces or bad bed leveling. You probably wont have to print the whole thing, just until you hear your print-head scraping across the print while positioning itself across the long leg sections.

Aligned printers will sounds smooth. You will hear a bumping or scraping for printers that aren't aligned properly.

In the picture you can see the bottom left section of the print looks bumpy while the top right is smooth. While printing I could hear the scraping as it went from top-right to bottom-left.