Problems configuring Nextgen Gallery

I’m having a problem figuring out how to configure Nextgen Gallery.
I have 163 images in one Gallery. The web page only displays 13 images.
In Gallery settings I have set 20 images per page.
In the gallery non of the images are excluded.
In other options, miscellaneous, maximum image count is 500.

I would like the page to display all images in thumbnail size and when I select one the full size displays on the same page. It would be nice to have a previous and next arrow.

The web page is at: http://theoffice.la/wood/portfolio/

https://wordpress.org/plugins/nextgen-gallery/