What is the tone, theme, imagery and figurative language of chapter 16 from "The Scarlet Letter"?The tone of the author

Chapter XVI of "The Scarlet Letter" characteristic of Romanticism, is rich in atmosphere and symbolism.  The gloom and chill of the forest reflects Hester's state of mind and the mood of the scene in which she furtively awaits the approach of Reverend Dimmesdale.

Almost every element mentioned in this chapter carries some symbolic significance.  The narrow footpath of the dense forest suggests the dark, narrow path that Hester has been on in her life; she perceives the forest as the "moral wilderness in which she had so long been wandering."  The sunshine fleeing every time Hester steps into it is the greyness of Puritan punishment shadows her life, shadows that ironically point to Pearl's appearing to absorb the sunshine.  Again in this chapter there is an allusion to the story of the Black Man and his mark, which have a special significance to Hester as she tells Pearl,

Once in my life, I met the Black Man.  The scarlet letter is his mark!

This remark carries a significant irony since Dimmesdale has, indeed, met the "Black Man" in Chillingworth, and he does, indeed, carry secretly a mark.

Hawthorne writes that

Pearl resembled the brook, inasmuch as the current of her life gushed from a wellpspring as mysterious, and had flowed through scenes shadowed as heavily with gloom.  But, unlike the little stream, she danced and sparkled, and prattled airily along her course.

However, unlike Pearl, the brook has undergone misfortune as the trees have flung great branches into it, compelling the brook to form eddies and black depths.  Thus, at times, the brook resembles Hester.  The Romantic sentiment of harmony with nature is expressed in Hester's words to Pearl,

'If thou hadst a sorrow of thine own, the brook might telll thee of it...even as it is telling me of mine!'

Continuing the tone of Romanticism, Pearl is sent away, singing, following the brook, and trying to sing with it in its melancholy voice:

But the little stream would not be comforted, and still kept telling its unintelligible secret of some very mournful mystery that had happened....So Pearl, who had enough of shadow in her own little life, chose to break off all acquaintance with this prepining blook.

Still Nature is somewhat in accord with man as the Reverend Dimmesdale appears, leaning on a stick.  The  "intense seclusion" of the forest does offer them privacy in their secret meeting.  Dimmesdale sees no need to dissemble as he walks with a staff and his hand over his heart.  There is no need to pretend before Hester, and Dimmesdale's weakness and his sense of guilt are apparent.