>>157185Well, because making a tread on 4chan requires that one also post an appropriate sized jpg, png or gif image, the original poster of this thread (generally called "OP" for short) chose to post an image demonstrating how to perform various knots. Ropes are commonly used by some individuals to restrain their partners for the purpose of sexual intercourse, and thus OP's image would prove helpful for those pursuing such activity. However, this practice is generally considered to be "deviant" and outside what is considered normal sexual practice. 4chan's "/d/" board is a part of the website wherein users share hentai pornography that depicts sexual acts that are not considered normal by society's standards, such as the aforementioned practice of restraining one's partner for the sake of sexual intercourse. I posted a cross-board link to /d/ with the implication that I misinterpreted the OP's image as being sexual and fetishistic in nature, rather than simply being an innocent guide to assist with outdoor activities. Such a ridiculous misinterpretation generates humour, which is further intensified by the fact that the post was early in the thread and leaving zero doubt as to whom my comment was directed at, as well as inducing frustration in the OP, as he was not recieving the informative responses he desired.
I hope this helps.