This doesn't make any sense. If Gracie pulls all her right feet off the sticky tape at the same time, why doesn't she fall over? And why don't her shoes come

This doesn't make any sense. If Gracie pulls all her right feet off the sticky tape at the same time, why doesn't she fall over? And why don't her shoes come off at the end when she tries to get off the sticky tape? The author obviously doesn't understand math at all. ;-)