Dan Harmon and Justin Roiland are huge pop culture fans and they’re both clearly sticklers for details. As a result there are tons of fun references and hidden secrets in the show. These secret easter eggs both hint at future events in the show, and even hint at connections between Rick and Morty and Gravity Falls. In the episode “Close Rick Counters of the Rick Kind” we see a portal open and it spews out a pen, a notepad and a question mark mug. This crosses over with the Gravity Falls episode “Society of the Blind Eye” in which Gruncle Stan loses those exact items into his own portal.
The creators have also included tons of little hints that Rick Sanchez might know that he’s in a TV show, and maybe it was Mr Poopy Butt Hole that told him about it. Rick does seem to address the audience more than any other character… in fact he’s one of only two to do it. Not only that but he has said things such as “I’m not going to answer a literal call to adventure”. This reference to classic story structure also implies that Rick knows he’s in a TV show, and isn’t just going to go on an adventure and entertain the audience if he’s not doing it for his own personal gain. He even talks about how many more seasons the show could run for.