The only time I've ever been in an actual show home was when my mum and I went to a new development near her house, just to be nosy.
It was very bland and matchy-matchy, but there was something odd about one of the bedrooms. It seemed really oddly proportioned or something.
It slowly dawned on me that the bed was very odd. It was supposed to be a double bedroom, and had a double bed in it, with two (immaculately plumped) pillows on each side. But it looked wrong, and the proportions seemed weird.
I happened to have a tape measure in my bag, so I measured it. They'd put in a 4' wide bed, 6" narrower than a standard double. To make it look like a double, they'd put smaller than standard size pillows on it. The bedside tables were tiny, too.
I couldn't help but wonder about the poor sods who bought what they thought was a 3 double-bedroom house off-plan, only to discover that it would only accommodate a double bed if you shoved it against one wall.
There were also big mirrors everywhere, presumably to deceive the eye about the size of the place.
So, imo a show home is one with teen-tiny furniture, lots of mirrors and very matchy-matchy.
Not a show home is an eclectic mix of styles and periods of furniture, original art and books which are for reading, not decoration. Oh, and a dog or cat happily snoozing, ideally on the less than perfect furniture.