in watching this film, as well as her other later films such as "A Child is waiting" and "Judgement at Nuremberg", I thought the same thing.
But also, I think this is the first time we got to see the real Judy. These three films, and especially this one where you can see the pain in her eyes, are the only 3 films where she was herself. She didn't have to pretend to be happy. As someone who knows what it's like to pretend to be happy for the outside world, I feel for Judy when I watch "Easter Parade" and all her other MGM gems because the smile on her face isn't real and she's not as happy as she looks.
It's unfortunate, but true. And it made Judy a greater actress than most people will ever understand because she made people believe she was truly happy. And part of me, at least in the early films like Oz and her exploits with Mickey Rooney, like to think she was. At least for a moment.