There's two parts to it.
1. AOC is a big advocate for forcing people to wear a mask as a way to fight covid. There's a big disagreement about the effectiveness of masks, and how one thinks about it seems to align with a person's political views, even though it should be a simple matter of scientific studies proving their effectiveness or not.
AOC recently went to Florida for a vacation. This in and of itself might seem an odd thing for her to do, because she's ultra liberal and New York where she's from is a pretty strong liberal state. Florida is a red state, governed by a Trump republican (Ron DeSantis. So New York is liberal and in favor of mask mandates, and Florida is conservative and not in favor of mask mandates.
Unfortunately when in Florida, she caught covid. This was after being seen at a party (the photo I attached to my previous post) without wearing a mask and clearly not practicing social distancing, another thing liberals seem to be more in favor of than conservatives. And btw, liberal political leaders not wearing masks when they publicly support forcing others to do so, is a common occurrence. (e.g. Mayor Breed in San Francisco, Gov. Newsom of California, and on and on.)
This is what many believe hypocritical behavior. Saying one thing, doing another. Saying one thing that applies to to others, but clearly believing based on behavior, that it doesn't apply to her.
For thee but not for me.
2. She recently was interviewed by Anderson Cooper of CNN, and he asked her about a tweet in which she said $21 trillion in Pentagon accounting errors could’ve paid for two-thirds of her Medicare-for-all proposal. (false, btw) So in response, she said that people shouldn’t focus on the details of what she says, but rather on the morality of her overall argument. She said: “There's a lot of people more concerned about being precisely, factually, and semantically correct than about being morally right.”
Here's a link to one story about this, but it's all over the internet:
https://townhall.com/tipsheet/leahbarkoukis/2019/01/07/aoc-it-doesnt-matter-if-im-factually-correct-about-things-n2538586
So I replied as I did to jab at her, but also since you said you didn't know about politics. I thought all of this was a good example of how politics work. btw, I could have probably found a conservative who is just as hypocritical. It's just that all this with AOC was currently in the news, so it was low hanging fruit.
Hope that helps explain.