I think that design is split in the ESI-LIE Duality between the LIE being the architect and structural engineer, and the ESI being the one who handles surface appearances.

I once asked a female ESI friend to give me her thoughts on house layout, because I thought she'd be good at aesthetics and the "feel" that certain layouts give to a house. I assumed this to be the case because my SLI ex had a lot of really perceptive thoughts on ergometric home design.
The ESI sat down and drew some floor layouts but she was hating every second of it. I asked her what the problem was, and she said "This is really out of my wheelhouse."

With a second ESI, we were driving through a nice neighborhood and she pointed to a house which had walls of mixed redwood and gray stone and said "That's nice!" It did look good, on the surface, but I wondered what the floor layout would be like. She seems to notice only what can be seen on the surface.

Another time, the second ESI showed me a picture frame that her cleaning lady had knocked off the wall and asked me if I could repair it. It had been assembled with contact cement and of course it dried out and was fragile after a few years. I said, "Lets go to the hardware store and get some epoxy."
When we got to the store and found the epoxy, she then asked if I could fix the hole in the wall that the hanging nail left when the picture fell. I said, "Sure. They make spackle for that, and if you have the original wall paint, I'll spackle the hole and you can paint it when it dries."
"What's spackle?"
I reached for this tube of wall spackle. "It's this stuff," I said.
"That's four dollars. I was just going to use toothpaste to fill the hole."
"Toothpaste?"
"Yes. I have some, and it doesn't cost four dollars."
"No. Just no. Here's four dollars. Buy the spackle."

LIE = Bones.
ESI = Skin.