Another possible word choice that might better meet your needs is exemplifies or is an example of.
It seems that the word 'reflection' is not so common in English for
When the words reflect and reflection are used in this context, it usually implies that some thing or action has influenced or is the reason for the state of the specific example you are currently referencing.
- This rotten apple reflects the poor food quality of this store.
- Your high salary is a reflection of your hard work.
- Her pink hat is a reflection of recent fashion trends.
- The ring on my finger reflects my status as a married man.
Something being a reflection is not synonymous with being an example, despite the words being interchangeable in some situations. I could never say something like "Thirteen is a reflection of prime numbers" because although thirteen is a prime number, nothing about prime numbers influences the number thirteen.
For your specific example, I would personally use reflection if trying to indicate that Wood's theorem was heavily influenced by the principle, example if it's one of many things that use the principle, and embody if it's one of the very best examples that most represent the principle.