Trying to get specific pieces of furniture inserted into image with Nano Banana

Place the new sofa on the same layer as the room with original sofa.

Use Nano Banana and Select All

the prompt I have used is:

replace the tan coloured sofa with the black sofa. keep the cushions and blue throw

OK, is this going to work?

Hmmm no it didn't. 😞

OK switcxhing to Firefly because it accepts a reference image.  

I saved the black sofa out to a JPG and uploaded it to Generitive Fill.

It asked for options (that I have not seen before) and I chose to 'insert' it.

It didn't do any better than if I'd removed background, placed and used Harmonize IMO

I have just realized that NB did do something after all

So I could have done it semi manually, and I didn't use Harmonize.

I actually tried NB again with a simplified prompt, and got the same result.