The glitch occurs when you try/buy the pattern. The glitch is only to yourself if you try it on.
The head, tail and back suddenly disappear once the Scratches pattern is on you. Also, when the pattern is bought, the missing head and tail is public to any players. It's sorta.. scary since there's floating head items and just limbs.
Here's another screenshot of the entire character missing the tail, head and back.
The character above, bought the pattern, while if you were to try on the pattern, Scratches wouldn't show up.
