Fine example. One of the only times Shizuka-chan is nude and Nobita isn't actually there to see it.
Anyway, here's a funny thing about Japanese censorship laws. Naked children are okay, but when it comes to adults, it gets tricky. I've seen a couple instances of naked female breasts, but only once, and they cover up the nipples usually. But when it comes to full nudity, they can let a child's...uh.... you know hang around in the breeze. That's why Crayon Shin-chan gets away with what he does, and it took a feature film for Bart Simpson to do the same thing. However, an adult's is pixilated or not shown entirely. Example? Kochikame (I wish I had clips to post, but I don't). In an episode where Ryutsu-san has a flashback story of something that happened to him when he was a kid, there was a bath house scene. But another episode featured Ryutsu naked, but it was pixilated. So there's a weird little censorship thingy there.
I believe things are changing, since newer Doraemon episodes actually cover up Shizuka-chan a little more.
They usually get away with a little more in mangas.