Guidelines for layout of component that can have variable sub components

I've been asked to design a component that lists objects on a page. The component needs to be able to display between 3 and 6 numbers of objects in the list. Here's what I have for 6 objects in a list:

The problem I'm having is that the client has come back to me and asked for how this component would display any number of between 3 an 16 objects and how it behaves on mobile. I thought simply adding more units of repeating things would be enough but the client wants 'variability'

For example, here's a design for 14 things:

This seems like a UI design issue and not strictly UX. But is there any obvious guidelines I can cite for displaying different numbers of things in a list, visually, and what considerations I have to bear in mind for mobile?