The "ee" doesn't have a specific meaning beyond expressing agreement. It's a way of adding a humorous, almost mocking tone to the agreement.
Here's how the meme typically functions:
* Scenario: Someone says something that is either obviously true or obviously incorrect.
* Response: "Mockingbird Joe" is used with the "ee" caption to express sarcastic agreement, often with a subtle implication that the person saying it is either an idiot or completely oblivious.
The meme's popularity comes from its ability to effectively communicate a subtle sense of humor and mockery in a way that's relatable to many people.