Mimetic buildings are designed to look like what they function as/for. The trend became popular in the US in the mid-20th century as a form of easily seen and understandable advertising. For example, diners and restaurants shaped like burgers, coffee cups, and donuts attracted customers for exactly what the building looks like: burgers, coffee, and donuts.
Historically, mimetic structures in the USA tended towards food shapes and were seen as trendy but silly. Today, architects are using this technique to design buildings that are aesthetically pleasing and long living but that also incorporate themes from the product. For example, the Apple store in Chicago sports clean, modern lines while also displaying a roof shaped like a MacBook cover.