In 1600s and 1700s, face shape was often thought to indicate a great deal about personality (a pseudo-scientific set of beliefs later codified as physiognomy). In addition to sending up these views—Beatrice is clearly not “modest,” no matter how pretty her forehead is—this passage also reveals Alsemero’s potions to be futile, as the non-virginal Beatrice is able to fake her reaction based on what she saw Diaphanta do. Repeatedly, then, this scene shows the danger of trusting appearances. Another detail worth noting: often, characters (namely Alsemero and Vermandero) use Beatrice’s middle name “Joanna” to convey tenderness and understanding toward her.