Gallery featured picture selection

I’m looking for a solution to do the following:

My client makes bronze statues and wants a picture gallery to show them. He has more than 1 picture for each statue but only wants 1 picture in the overview of the gallery. When you click a picture, the lightbox opens and then you can scroll trough all the pictures.
Is there a possibility to do this within wordpress???

ex: on the gallery page in tab 50-100cm you have 3 images of the same statue but on this overview he wants only 1 image to show up. When clicking you can scroll trough the others too.

Help would be great!

The page I need help with: [log in to see the link]