Hey there Alex,
thanks a lot for your kind words!
Obviously, I uploaded this not to brag with some insane realism, but to share a simple and sympathetic idea of presenting a very early project phase (that has little to no input) in an interesting and still kinda realistic way. Me and the client are very happy and plan to use this optic in future similar situaions, too.
As for your question - the setup is as simple as it gets - a studio HDRI - that's it. Just pick one that fits your needs and meets you taste. The current one I've used is the white studio interior from HDRI Haven.
I mean, you can surely go further and build a whole studio around, place the scale model on a table and so be able to make far views (of the scale model, being placed on a table and lit up with some table lamp). This would emphasize the scale even further... In my case, as it was a commercial project, I didn't want to make it more expensive for the client, without any added value for them. And as the next project was waiting, after this was done, I also didn't have the time for that. So I uploaded it as it was delivered.
Hope this helps and wish you all the best!
Teo/Helldoor