The shield symbolizes pentangle and represents the five virtues of knights: generosity, friendship, courtesy, chastity, and piety. Gawain is overcome with all these great virtues after the miracle and long journey he went on. Also, another example of Gawain's church values is the idea of chivalry. Chivalry provides an intriguing set of values which he tries to implement in life, but most of all remain conscious of his own weakness. His time in the wild, for example his flinching at the Green Knight's axe, and his willingness to accept the lady's offering of the green girdle. These actions taught him that though he may be the most chivalrous knight, he is still human and mistakes will be made. The final step in the evolution of the church ends with "Lady of Shallot " and the collapse of the church values. .
"The Lady of Shallot" is isolated from the world and has no direct view of the world in her eyes. She sees the humanity from a small worldview which is very different from others. To the world, she does not exist and wants to be put back into society but she knows that won't happen, so she waits her imminent and fatal death. The curse that is cast upon her stated that she can only look at society through the mirror she has. This symbolizes the Lady's pure will to sacrifice herself and view the world from an isolated standpoint. This also shows that she has given up on hope that god will help her and she knows that death is upon her. The change in church values can be related to the three sisters of Greek mythology and how the first sister expressed the weaves and thread of life, the second sister symbolizes the measure on the thread (length) of life, and the third woman cuts the thread of life (Manwell Lecture on LOS analysis and connections to the Church).
Irony is shown in many different ways in all the stories written in the Arthurian Legend time period. A great example is in "The Lady of Shallot,"" and how the knight passing by the Lady's window encounters with the lady.