Yeah, I'd consider carving something out of stone to be the minimum, "building" one out of cast concrete or whatever seems a different project.
I wouldn't consider the Bass Pro Shops Pyramid to be the "same thing" as the Pyramids at Giza, for the same reasons.
I may be dating myself a bit here, but when I was growing up I used to go see Disney on Ice shows at the Memphis Pyramid rather than it being a Bass Pro Shop...