The discussion revolves around calculating beat frequency from a given graph showing wavelengths over time. Participants analyze the number of wavelengths and the time interval, leading to a calculated frequency of 50 Hz. There is confusion regarding whether this frequency represents one of the source frequencies or the resultant frequency. The consensus suggests that the calculated frequency is the average of the two source frequencies, despite discrepancies in the problem statement. Participants agree that the author may have misrepresented the beat frequency in the question.