I actually have a theory on that, I think Gates Mcfadden and Marina Sirtis both wanted to direct an episode, For CV padding or because the men get to do it or w/e. Anyway, they both go to Rick Berman and ask to direct and he decides to make it a competition. He makes them go off and write an episode script starring the other actress and whoever writes the worse episode gets to Direct and the loser has to do the episode. Gates submitted what became Sub Rosa but Marina Sirtis refused to the episode so Gates, the stand up gal she is decided to act in the episode she wrote too. I also think the script Sirtis wrote eventually became the episode masks.