Jupiter is to be used as an advertising billboard), to be seen by passing spacecraft. The main Earth negotiator reveals to his colleagues that he has outsmarted the aliens, who clearly are not experienced hagglers, having neglected the other Jovian planets.
Jupiter is to be used as an advertising platform for space travelers to see. The Earth negotiator has outmaneuvered the aliens, who are not skilled at negotiation and have overlooked other Jovian planets.