The Script Editor logo used to be a physical paper with the AppleScript logo printed on it correctly, but seen at an angle in perspective (so the AppleScript logo was tilted as a result), with a pen on top.

When they switched from the original physical-looking icons, whichever designer drew the new one wasn't paying attention and apparently didn't understand the physical context of the previous logo and they screwed up the revision by keeping the (now-nonsensical) tilt.

https://web.archive.org/web/20101207035423if_/http://upload....

thank you for unlocking the mystery