Ahh i see. This is another good learning moment for you. Have you heard of the term colloquialism before? Essentially, a colloquialism is used in or characteristic of familiar and informal conversation.

People typically use the term "shill" non-literally or sarcastically in casual conversation to criticize someone who passionately supports a cause, even if there’s no secret agenda. A good example is the way people use the word "literally" today. The word "literally" means 'word for word' or 'not figuratively'. However, most people use it today to intensify or dramatize their statements e.g I was so hungry, I literally had to eat the whole fridge. You can see that "literally" is used figuratively here

So that was my intention when using the word "shill". Call it hyperbolic or rhetorical if you will.