First, four people each post a word, one after the other. When the fourth person posts their word, they also perform a Google images search with those four words and embeds a (safe for work) image from the first 3 results. The next person then post another word following that image to restart the chain with.

To embed an image: [img]Url of image here[/img]. Remove any extra text that comes after the .jpg or the .png