They say it's hair and it grows. Try telling that to someone when they just got their hair cut and found out that the haircut looks terrible on them.
Hair grows, but at too slow a rate to change the hairstyle over night.
Chances are the hairdresser who cut their hair did not look at their face shape or bother to discuss the hairstyle with the client first. If you discuss hairstyles with clients and tell them they would look better in another hairstyle than the one they originally wanted, most of the time they are eager to listen. The reason for this is there are four different face shapes. There is the heart shaped face that is the ideal face shape for all hairstyles. Then there's the oval face shape, people with this face shape can wear long hair.