I guess it's a more philosophical point, but the Yoneda lemma can be interpreted as "if you know how some thing X interacts with every thing (of the same kind), then you know X completely".
For example if you have, say some specific physical body X, then if you know, for every physical body how it interacts if you throw it at X, then you know everything about X.
I think that example encapsulates the idea of how the Yoneda lemma is mostly applied: just throw everything at the object you want to understand, then if you know what happens there, you understand the object.