1) A monster grabs someone by the face so she licks its hand to make it drop her.
Would in any situation you lick an attacker, and in any situation would that attack let you go from being licked. That only works because its goofy and the writer wanted it to work. Any person in his own reality would know this wouldn't work. Hence meta.
2) A character changes the subject and asks someone if they want to eat a centipede, then eats it.
once again, no one would just pick up a centipede and eat it out of the blue (blw centipedes are venomous.) This is just to show someone is goofy and not acting normal like the have done to Harley in DC. It's random meta as it's for the readers sake, not the people in the story.
3) This moment:
Then a dark figure pins him down.
"I'm only going to ask this once. I will not repeat myself. Where's the chosen one, pretender?"
Heiroe: He's fucking your grandmother!
This is using a popular insult from our world. And not even a good insult. If the hero was actually pinned down and in dire circumstances, a mom joke would not be the first thing that comes out of his mouth. He is acting as if he isn't in real danger. So the joke is for the readers as in his reality, he would be dealing with the problem at hand, not make off the cuff mom jokes.
4) “Windows are just doors the government doesn’t want you to know about”
I actually don't have a problem with this if it's part of a longer narrative.