Well, if Tim Buton did it the same way as he did Nightmare Before
Christmas, then he has a wall full of little clay interchangeable heads
with different expressions that he uses stop motion to switch and
animate.
Ahah, I was right. A quick search of
www.imdb.com trivia revealed this:
<div class="quote"><div class="quotetitle">? quoting www.IMDB.com:</div><div class="quotetext">
<ul class="trivia">
[*] The puppets were made from stainless steel armatures covered with silicone skin.
</li>[*] The first stop-motion feature to be edited using Apple's Final Cut Pro.
[*] As an indication of the painstaking nature of stop-motion
animation, it took the animators 28 separate shots to make the bride
blink.</li>
[*] The puppets used neither of the industry standards of replaceable heads (like those used on
The Nightmare Before Christmas (1993)) or replaceable mouths (like those used by Aardman Studios in
Wallace & Gromit in The Curse of the Were-Rabbit
(2005)) but instead used precision crafted clockwork heads, adjusted by
hidden keys. This allowed for unprecedented subtlety, but was
apparently even more painstaking than the already notoriously arduous
animation. One animator even reported having recurring nightmares of
adjusting his own facial expression in this fashion.</li>
[*] Small moving elements, such as candle flames, were photographed in MiniDV.
</li>
</ul>
</div></div>