I always like seeing stuff next to cels, like 
contextual stuff (hey, just seeing a cel is a 
spoiler for a scene, so you might as well go for 
broke).  And why people like particular cels is 
always interesting to find out about too.  But as 
for exactly when a cel occurs?  Ok, it's 
interesting but it's probably going to take 
longer to do than it'd be worth.