What does it mean that elephants didn't take part in this brain teaser at the animal convention?

This is a sketch by Zhao Benshan and Song Dandan. The exact words are like this. Song Dandan told a cold joke: How can I put an elephant in the refrigerator? A: In three steps,

Step 1, open the refrigerator door; Step two, put the elephant in; Step three, close the refrigerator door. Then he asked, who didn't attend the zoo meeting? Answer: the elephant didn't participate, because the elephant is still in the refrigerator and hasn't come out yet! ! It should be like this. You can have a look.