a different gallery for each post

1. Create a different slideshow for each exposition.
2. At the bottom of the slide settings you’ll find the shortcode for that particular slideshow; e.g. [meteor_slideshow].
3. paste the shortcode into the page / post you want to display it in.

I agree that can be confusing [it is to me too], however…
Below is the correct syntax as suggested in the documentation by the author. (http://jleuze.com/adding-multiple-slideshows-with-different-sizes/)

[meteor_slideshow slideshow="jupiter"]

Here ‘jupiter’ is the name of the slideshow to be displayed.
Replace by your own slideshow-name.