Read this strip at gocomics.com.
This looks very much like a pop culture reference of the time, the candelabrum on the piano being a trademark of popular pianist Liberache. Or maybe it's just something pianists did at the time? It is rare that Charlie Brown and Shermy are more disgusted with commercialism than Schroeder, Christmas specials notwithstanding.
Ominously, Schroeder's little gesture seems to have enraptured Lucy.