From the moment that Mitch and Blanche are introduced, it is clear to the audience that they have a 'certain interest' in one another. Immediately previous to their meeting, Mitch talks of his 'sick mother'. This reveals a sensitive side to his character, which contrasts with the vulgarity and coarseness of his peers. Blanche has clearly been unimpressed by the manners of Stanley and his other friends, which hints that she will like Mitch rather better.
<Tab/>Mitch leaves the room just before Blanche enters. Their rather unexpected meeting at the bathroom door draws attention…