A Facebook post featuring what appears to be a very large snake is imploring users to write the number 6 as a comment and to “look what happens to the picture”.
Write number 6, and then look what will happen to the picture.
Obviously the picture in the image is fake since the snake has been super imposed onto the image, thus is blurred when compared to the people around it.
And to confirm, nothing happens at all when you type anything onto the image. This is just a ploy to lure people into engaging with the post so the post can spread quickly across social media. Lots of engagement means the post will appear in more peoples newsfeeds, who in turn will interact with the post and further increase the engagement.
It is essentially a form of like-farming, where spammers are using deception to lure Facebook users into interacting with their posts.