Scaling viewable area mobile website

Hello Everyone,

I am working with a company to get their Sketchfab models for use on both their main website and their mobile site. I work on the 3d side of things but I wanted to see if I could help find a solution for an issue they are having.

Everything looks great on their main site. The viewable area for the mobile comes up with no problems. But when it comes to the viewable area on their mobile site it looks as if it does on the main site and the viewable area for the model does not scale down for mobile.

Are they possibly missing web coding that would make the viewable scale for a mobile phone? Is there a easy solution to fix it?

Thanks for your help ahead of time!

Is it possible for you to show screenshots of the situation? That would make it easier to help out.
In my experience the 3D model is centered nicely when changing screen sizes and proportions.