sprite crop

When I open sprite editor I can crop transparent edges. OK. As I can see from the tooltip when I hover the crop button: "hold shift to crop the entire animation". The question is: what does it mean "crop the entire animation"? Which way does it work? I can see 2 ways, which exactly it may work

1) For example if you have 8 frames of animation in your sprite, crop button will crop transparent edges for all frames in your spritesheet

or so

2) If you hold shift when click on crop button it will crop ALL transparent space in your sprite

And are there any built-in features to crop the hole sprite from transparent space in C2 ?

Thanks in advance

Holding shift does the same as going through every frame and clicking the button for each of them.

it works for some other buttons too.