As evidenced by the tweet explaining the premise behind the episode, the episode was a reference to Trump University.
Homer seeing Lisa in his mind telling him that he's crushing her while he is teaching his class as professor is a reference to how Jimmy Neutron sees visions in his mind in the Nickelodeon cartoon, "Jimmy Neutron: Boy Genius".
This is one of the few episodes where Lisa drinks alcohol (in this case, red wine) and acts drunk. This is also the second episode where Lisa drinks red wine, the first being "The Italian Bob".
Lisa drinks red wine in this episode, but drinking alcohol is actually very dangerous for people under the age of 21, including Lisa, who's 8. However, despite drinking alcohol too much under the age of 21 can possibly kill you, Lisa didn't die when she drank alcohol in this episode, along with "The Italian Bob" and "Selma's Choice". Marge or Homer could've stored the alcohol away from Lisa for a while and somehow, in this episode, drank the wine glass that was near Homer. After that, her parents could've stored all the alcohol away from Lisa so that way she won't die from alcohol drinking.