The EEVBlog YouTube channel (someone else already linked it) covered the implausible shredding mechanism in the Banksy video. https://www.youtube.com/watch?v=SdKdQWhlNTY
In addition to the impossible angle, the position also does not fit a plausible paper path, and you can also see the curvature indicative of being stuck in the roller of a traditional shredder for days/weeks/months on the bottom of the paper coming out.