Brush what you mean
Paint over the sofa, the floor or one wall and only that region is regenerated. The rest of the pixels are untouched.
Precision
Change the floor. Leave everything else alone.
Whole room redesigns are useful once. After that you usually want to test a single decision, which is what this is for.
Compare like for like
Because only one thing moved, the comparison is honest. Two full redesigns differ in a hundred ways and tell you nothing.
Stack the decisions
Settle the flooring, then the walls, then the furniture, each on top of the last.