When Massing mentions that Ulanovsky had told her he was not her boss and that they were "both waiting for the boss", she implies that he ranked closely to her. However, Ulanovsky meant not that "the" (their) boss but that "her" boss was coming (Valentin Markin).
When Massing suggests that Ulanovsky is near her in status by stating they are both awaiting their superior, however, Ulanovsky corrects this to mean "she" (Massing's) superior is approaching (Valentin Markin).