Amanda Bynes Mug Shot -- Short Hair and a Scowl

Amanda Bynes had to remove her platinum blonde wig when she posed for her mug shot last night ... revealing a super short hair cut ... and Bynes didn't appear happy about it.

Bynes sported a scowl and a black shirt when she posed for the photo ... following a bong-throwing arrest in NYC last night.

The 27-year-old actress arrived to court this morning to face a judge -- wearing the wig again -- but it was clear she didn't want to be photographed.