Another sentence without a verb. A "nominal" sentence. But is it a complete sentence or just a phrase? And, why should we have to wonder what the "inferred" or "implied" verb is?
This is just a question where you can choose from one or the other. Like in "tv or cinema?". Or "blueberries with or without cream?". The speaker/writer probably wants to know your preference, or maybe starts with this phrase before explaining his own views. There is no implied verb here.