A boiling plastic spreader
It’s tempting to skip reading the instructions on any product or instrument we buy, but if you don’t want to make any silly mistakes, reading the instructions is the best thing to do. At the worst, you’ll confirm that you were about to do everything correctly anyway. And at best, you’ll prevent messes like this one.
This brand-new iron came with a plastic film on its surface, which had a very obvious sticker stating that it must be removed before use. But this person either didn’t see the sticker at all or simply forgot, and so their iron transformed into a boiling plastic spreader. That’s not what you want. You can only hope they’ve learned their lesson.