You can go to the list of new contracts for Customs and Border Protection to see what the Trump administration wants for its wall. For example:
That's a screenshot. So it needs to be reinforced concrete, "imposing," and not amenable to ladders. It should resist a sledgehammer for an hour. It should be impervious to a tunnel up to six feet under (is there an implied pun there?).
And of course it should be aesthetically pleasing, with different colors and textures. It does not specify motif.