At first glance, this drawing looks like nothing special, just an odd design of lines, but then you notice the two bolded lines. They look like they are different sizes, but are they? No! They are the exact same length. Tricky… very tricky.
To learn how to create this optical illusion on paper yourself, this video will show you the steps to drawing the figure. Just remember to draw those two lines exactly the same length. One will seem a little bit shorter than the other, even while you're still drawing it.