You can play around with the Responsive Gallery Grid settings in the sidebar. Changing a setting will reload the demo gallery with the applied settings.
RGG Tester
<!-- wp:gallery -->
<figure class="wp-block-gallery has-nested-images columns-default is-cropped">
<!-- wp:image {"id":4,"sizeSlug":"large","linkDestination":"none"} -->
<figure class="wp-block-image size-large"><img src="https://responsive-gallery-grid.bdwm.be/wp-content/uploads/2013/04/rgg-ss2.png" alt="" class="wp-image-4"/></figure>
<!-- /wp:image -->
<!-- wp:image {"id":5,"sizeSlug":"large","linkDestination":"none"} -->
<figure class="wp-block-image size-large"><img src="https://responsive-gallery-grid.bdwm.be/wp-content/uploads/2013/04/rgg-ss3.png" alt="" class="wp-image-5"/></figure>
<!-- /wp:image -->
<!-- wp:image {"id":9,"sizeSlug":"large","linkDestination":"none"} -->
<figure class="wp-block-image size-large"><img src="https://responsive-gallery-grid.bdwm.be/wp-content/uploads/2013/04/299912579_b776aa8383_z.jpg" alt="" class="wp-image-9"/></figure>
<!-- /wp:image -->
<!-- wp:image {"id":10,"sizeSlug":"large","linkDestination":"none"} -->
<figure class="wp-block-image size-large"><img src="https://responsive-gallery-grid.bdwm.be/wp-content/uploads/2013/04/875318063_72cbfd5bd3_z.jpg" alt="" class="wp-image-10"/></figure>
<!-- /wp:image -->
<!-- wp:image {"id":11,"sizeSlug":"large","linkDestination":"none"} -->
<figure class="wp-block-image size-large"><img src="https://responsive-gallery-grid.bdwm.be/wp-content/uploads/2013/04/1162371450_ca3c245c86_z.jpg" alt="" class="wp-image-11"/></figure>
<!-- /wp:image -->
<!-- wp:image {"id":12,"sizeSlug":"large","linkDestination":"none"} -->
<figure class="wp-block-image size-large"><img src="https://responsive-gallery-grid.bdwm.be/wp-content/uploads/2013/04/2446795991_8cfae1e847_z.jpg" alt="" class="wp-image-12"/></figure>
<!-- /wp:image -->
<!-- wp:image {"id":13,"sizeSlug":"large","linkDestination":"none"} -->
<figure class="wp-block-image size-large"><img src="https://responsive-gallery-grid.bdwm.be/wp-content/uploads/2013/04/2527625329_01ae57af4d_z.jpg" alt="" class="wp-image-13"/></figure>
<!-- /wp:image -->
<!-- wp:image {"id":14,"sizeSlug":"large","linkDestination":"none"} -->
<figure class="wp-block-image size-large"><img src="https://responsive-gallery-grid.bdwm.be/wp-content/uploads/2013/04/2527628573_a8fda2f219_z.jpg" alt="" class="wp-image-14"/></figure>
<!-- /wp:image -->
<!-- wp:image {"id":15,"sizeSlug":"large","linkDestination":"none"} -->
<figure class="wp-block-image size-large"><img src="https://responsive-gallery-grid.bdwm.be/wp-content/uploads/2013/04/3003889636_2be2ffd427_z.jpg" alt="" class="wp-image-15"/></figure>
<!-- /wp:image -->
<!-- wp:image {"id":16,"sizeSlug":"large","linkDestination":"none"} -->
<figure class="wp-block-image size-large"><img src="https://responsive-gallery-grid.bdwm.be/wp-content/uploads/2013/04/3551605462_a4c04535a9_z.jpg" alt="" class="wp-image-16"/></figure>
<!-- /wp:image -->
<!-- wp:image {"id":17,"sizeSlug":"large","linkDestination":"none"} -->
<figure class="wp-block-image size-large"><img src="https://responsive-gallery-grid.bdwm.be/wp-content/uploads/2013/04/3597963773_b042e887f0_z.jpg" alt="" class="wp-image-17"/></figure>
<!-- /wp:image -->
<!-- wp:image {"id":18,"sizeSlug":"large","linkDestination":"none"} -->
<figure class="wp-block-image size-large"><img src="https://responsive-gallery-grid.bdwm.be/wp-content/uploads/2013/04/3608316767_5a5fa28ab1_z.jpg" alt="" class="wp-image-18"/></figure>
<!-- /wp:image -->
</figure>
<!-- /wp:gallery -->
