The wealthy and fashionable East Egg residents hide their unattractive qualities underneath light, dreamy appearances.
It influences a lot because, as the story is evolving so is the setting.
It matters because, without setting there's no story.
I believe that setting is the most important part of a story because, it tells u many things..
For Example :
TIME /PLACE /BACKGROUND OF STORY /AND WHERE SOMETHING TAKES PLACE..
in the house, park, pools, hotels, movies, Etc....
Treasure in the first usage means precious gems like gold or silver . In its second use, it means to value something.
Hope this helps. We could help more if I had the poem for sure posted here but this is the meaning from the poem I think you are talking about.
Have a great day!
