But the person in the Pre line got to keep their shoes on!
Although on my last flight I did learn that Nutella is a liquid. Maybe I should have frozen it?
Heathrow's FAQ: "Do I need to remove my shoes at security? Only if you’re asked. Some passengers will be asked to remove shoes in order for them to be x-rayed."
Gatwick's FAQ: "You may be asked to remove your shoes and belt before going through the security archway."