"In the cooperation phase, both players ... contribute simultaneously ... to a common pot, unaware of the partner’s contribution." The higher-ranked player then gets priority in determining how the payoff is split.
Who goes to work without agreeing on a salary?? Who co-founds a company without agreeing to an equity split??
The connotation for the so-called "lower ranked player" is also misleading, as in the real world the employer is more similar to their "lower ranked player": the employer usually commits to paying the employee around three months' worth of salary first. The employee then gets to choose to slack off or work hard. So, in a sense, the employee gets to choose how to divide the payoff: the employee always gets the salary, while the employer gets (output - salary). Of course, in the real world the game is then iterated, as the employer gets to choose to fire the employee or continue the relationship.
Any experiment in game theory that doesn't involve iteration is highly unrealistic -- the fact that we have a reputation to keep and have to deal with each other over and over again is pretty darn important! Frankly I'm a little bit disappointed that Nature has chosen to publish this paper, as I don't see what insight it offers.