The discussion centers on understanding the concepts related to polarization, particularly in the context of Brewster's angle. The poster expresses clarity on one aspect (A) but seeks guidance on the underlying principles for other parts (B, C, and D). They reference atmospheric phenomena, specifically blue skies and red sunsets, to illustrate their inquiry. The thread invites suggestions for deeper comprehension of these concepts. Overall, it highlights the need for clarification on the complexities of polarization in different scenarios.