Collapsing Elements (with Video)

Hi Folks,

currently working with collapsing Elements and I dont get it.
I have read the tutorial ( ), but it doesnt help me to understand it.

Now I made an little video:

Here you see several elements, which has the collapsing function applied.
If you click “button1” the page stays the same. Click “button2” website dont change.
But if you click “button3,button4” website is moving the elements.

Now I take the vectorimage (The guy with the umbrella) and move it up to “button4”.
All clear, the website is working fine.

But why?

One thing I recognized is:
If you add an animation to an picture, and hide it for collapsing the code will NOT work!

The element will not appear anymore! Something which wix-team should fix.
Because elements could move in an much smoother way into the website.