Greenness
The text is rife with descriptions of greenness: from the Green Knight's elaborate outfit to the surprising appearance of the green "chapel," Sir Gawain and the Green Knight relies on a color imagery to suggest the poem's investment in the natural world. As such, the poem has become a popular source for ecocritical research of Medieval English literature, which studies the relationship between literature, man, and the natural world.
Hunting and Butchering
Readers may be surprised by the amount of detail provided in the descriptions of Bertilak's hunts and subsequent butchering of the animals he and his men catch. However, these heavily detailed scenes help emphasize the importance of hunting as a social phenomenon: rules are strictly followed according to one's social station, and the text presents hunting and butchering as art forms whose parameters must be firmly heeded by all involved.
Clothing
Clothing is also depicted as an important social indicator in the poem. The Green Knight, of course, is dressed in lavish green clothing that emphasizes both his relationship to nature and his wealth as a knight. Gawain's clothing is similarly extravagant and adorned with symbols that suggest his virtuous reputation. When Lady Bertilak attempts to seduce Gawain for the last time, she is scantily-clad and adorned with jewels to suggest her romantic intentions. What characters wear (or do not wear) often indicates how they will act.
Seasons
The changing of seasons is an important image in the poem, and indeed each season receives its own detailed description as Gawain abides by the one-year waiting period requested by the Green Knight. These descriptions of the changing season are metaphorical representations of life, which moves from birth, growth, and prosperity to decay, old age, and death.
