Rick roll refers to tricking someone into opening the YouTube video for Rick Ashley’s Never Gonna Give You Up. Knives are used to cut things, and in this case the father was arranging them to look like the loss comic. Without the context, the layout of the knives appears to just be a hieroglyph, which is a symbol used to convey information.
When you bring this all together, you get a dad having fun with his kids by ironically referencing memes he doesn’t understand. Kind of like how grandma used to call every video game console a Nintendo or every Pokémon a pikachu.
The way they showed the reasoning of the AI using a scratchpad makes it very hard not to believe these large language models are not intelligent. This study seems to imply some self awareness/self preservation behaviors from the AI.