what is the mood of the crowd, and why is their attention focused on the door?

Chapter I of "The Scarlet Letter" presents a tableau of the Puritans.  Standing outside the prison door "studded with iron spikes" is "a throng of bearded men, in sad-couloured garment, and grey, steeple-crowned hoods..."   The picture here is of a people devoid of the emotion of a less stringent culture.  Later in his novel, Hawthorne writes of the New England holiday and, again, remarks upon the Puritans have lost the art of joy like their English ancestors.  Here is a people whose faith has removed the color of life from them.  Yet, devoid as they are of passion and the joie de vivre that other people free in a new country might have, these Puritans who fled religious persecution are now persecuting one of their own.  And, ironically, if they are so pure and strict, why is there the need of a prison?

The mood of the crowd is grey like their clothing, accusatory like their prison.  In the midst of this somber mood, there stands a solitary rose, suggestive of Hester's passion and stalwart pride.