If you are like me, you immediately thought what kind of patent did Post get for its bagged cereal displays. They received a design patent -- D798,091 -- for the claimed ornamental design -- which is represented by the solid lines in Figure 1. In other words, they received a patent on the front trapezoidal display element.
Design patents are important, but they are narrower than utility patents. They do not protect functional features of an invention, and they can be designed around by changing the overall appearance of the competing product.
The shapes of the front trapezoidal display elements are not the same, and the complaint admits it but tries to minimize the difference by stating that the shapes "are virtually identical".
Also, the alleged infringing product has an inscribed GM logo on it.
Are these differences enough for GM to avoid infringement? We will have to see.
Finally, the complaint is interesting because Post focuses on GM entire merchandising system (the front display and the stand) and calls it an Infringing Merchandising System despite only having patent protection over the front trapezoidal display elements.