Not the chocolate kind, the DVD extras. The secrets. The small, special things that only certain people will look for or notice.
My thesis had a few Easter Eggs. As a mathematician, it was about proving much stronger results than I needed for my theorems. As a metaphor, I needed to boil an egg, but what I did was write a cookbook called Everything Eggs: An Infinite Recipe Book With Yolks.
On a few occasions in my thesis I was able to include little things that were much more impressive once you looked closer. Little things, nice, but not necessary, but a contribution in their own way.
What are the things you’re proud of in your work even if others might not find them or know to look? Where are they hidden? Why did you do them? What do they mean?
Your thesis and research Easter Eggs could help or delight lots of people if they find them. Don’t forget them when you review your progress. They add something special to your research journey.