What is the “would” meme and why is it everywhere?

The would meme consists of photos of a person, animal, or anything with a mouth, typically speaking into a microphone, with a caption that simply says "would." This may confuse anyone who is not chronically online and is unfamiliar with the concept of "hornyposting."

For the rest of us, we understand that this single word is meant as a declaration that the person posting the meme is willing to engage in sexual contact with whomever the image is referring to.