My favorite thing about the logo is an apt decorative/symbolic element which I've covered with a brown rectangle. What is it? (Go ahead and Google this one if you think your search skills are better than mine.)
Solution
It's a pair of acorns. Here's the original picture.
Congratulations to yesterday's solvers Hazel, Dr. Yetman, and Mr. Gregg. Thanks to everybody who made a guess!
Ten years later, Dr. Shapiro revived Puzzle of the Day at Proof School, writing each day's puzzle on a name tag. After 600 puzzles or so, he was just starting to feel normal about students reading his chest all the time when campus closed and the puzzle, like the rest of our lives, moved online. New puzzles are posted daily on school days.
Want to catch up on old PotDs? There's an archive currently containing puzzles from March to December 2020.