Part of the job of interior design is delivering the promised images in … yknow, physical reality? How are you going from nano banana images to actual plans, materials, finishes, products, paint codes, … ?

I just gave the renders to the cabinet makers and they had no problems recreating.

Interesting. I model interior architecture as "here's $xxxK, make it nice" and they do a bunch of work to figure out what you mean by nice, and a bunch more work to codify your definition of nice into, like, SKUs of sconces and so on. Seems like NB helped you figure out your definition of nice, and your subcontractor had a good designer on staff to execute on that.

A sufficiently detailed render won't require a designer to figure out the materials. Any (reasonably competent) contractor can take a sufficiently detailed render with him to the store and find matching products. At least assuming the thing in the render actually exists.

He can also send back a picture of the real product for approval. I think the primary difference here is the level of involvement. A quick consult and then the professional "makes it all work" versus hands on design with the client figuring out all the details for himself.

A designer knows things from experience and would be aware of small details that if not designed correctly, become very apparent when built in reality.

The interior designer doesn't really do squat. They can do plan drawings and have some off the shelf cupboards and furniture. They don't implement anything

Presumably you give the render to a designer and they recreate it using real materials.

not the op, but this is what i did too and bypassed the designer. I iterated with nano banana and gave the result to the company that builds the kitchen. the middleman is gone now.

interesting! Discovered any prompting best practices while iterating with nano banana?

This is what I would do too