[RWilson]

You're technically right. For reference, look and feel fall under "trade dress" [http://www.ivanhoffman.com/tradedress.html]. In brief, the relevant case law is:

"To recover for trade dress infringement ... a plaintiff must prove by a preponderance of the evidence: (1) that its trade dress has obtained “secondary meaning” in the marketplace; (2) that the trade dress of the two competing products is confusingly similar; and (3) that the appropriated features of the trade dress are primarily nonfunctional."

Continuing ...

"Strength of ... trade dress depends upon the interplay of two elements, the uniqueness of the trade dress and the investment in imbuing a trade dress with secondary meaning."

... which makes trade dress difficult to prove, even to only a preponderance of the evidence.