It doesn't violate any rules.. Imagine both the "speaker" and the "text" are being updated by separate threads. A program that would eventually display the behavior in this meme is simple, and I'm a bit embarrassed to have written it because of this comment:

#include <pthread.h>
#include <stdio.h>

char* speakers[] = {
    "Alice",
    "Bob"
};
int speaker = 0;

void* change_speaker(void* arg)
{
    (void)arg;

    for (;;) {
        speaker = speaker == 0 ? 1 : 0;
    }
}

char* texts[] = {
    "Hi Bob",
    "Hi Alice, what's up?",
    "Not much Bob",
};
int text = 0;

void* change_text(void* arg)
{
    (void)arg;
    for (;;) {
        switch (text) {
        case 0:
            text = 1;
            break;
        case 1:
            text = 2;
            break;
        case 2:
            text = 0;
            break;
        }
    }
}

int main(int argc, char* argv[])
{
    pthread_t speaker_swapper, text_swapper;

    pthread_create(&text_swapper, NULL, change_text, NULL);
    pthread_create(&speaker_swapper, NULL, change_speaker, NULL);
    for (int i = 0; i < 3; ++i) {
        printf("%s: %s\n", speakers[speaker], texts[text]);
    }
}

I don't see OP explaining it anywhere.

It's just threads running out of order.

Why are you all overengineering the joke this much?

Oh, I guess that makes sense. One person asks if the other is an expert, they reply they read the for dummies book, cue comically aggressive response.

There's so much going on in this exchange, including two separate jokes as well as weird multi-person race conditions, that I couldn't reverse engineer it.