Look, parking is hard sometimes. It's especially hard when you're in a busy car park, and everybody is competing for space. The people who design car parks try to help you out with this, by drawing clear white lines to indicate where you can leave your car, and how much space you should take up. All you need to do is line your car up with the space, and you've done your job. Regardless of what this driver believes, these white lines also apply to Mustangs.
As the driver decided to take up 20% of someone else's parking space, someone else has occupied the remaining 80%, and left the Mustang driver with nowhere to go. They're completely boxed in by a pair of everyday heroes, who've decided to teach them a lesson about parking like a clown. We wonder how long they had to wait when they got back to their car?