It’s a shame that this “candid” photo isn’t really a candid photo at all. Basically, production companies back in the day would release “candid” photos like this to the press. When reading more about Judy Garland, it seems that she never had one stable moment in her life.
Also, if you were wondering why you can’t remember her skirt being that short, it’s because it’s not. It’s the end of her shirt and someone just stole her dress.