In my mind, setting is everything. Food, drink, costume, social mores all make the setting. So does the science and technology. The advent of the smart phone is plenty of proof of that.
Steampunk is a visual aesthetic as much as a literary genre, IMO. The affectations which define a Steampunk convention costume are clearly presented (sometimes outlandishly presented) Victorian "sci-fi" equipment, weapons and gadgets.
Technology is everywhere in the world. It affects transport, sanitation, medicine, industry and recreation. One of my favorite gadgets from my current novel "The Sauder Diaries - By Any Other Name" is the The “Electro-Magnetic Inductive Polar Aerostat Lift Engine,” or “EMIPALE”. Essentially it uses a period analog computer and electromagnetic repulsion to add lift to a laden airship. It's pretty much pixie dust and happy thoughts based on current-day, modern science. However, it was an area of actual interest and research in the Victorian era.
I have a lot of fun dreaming up sci-tech to use in my story, based on what would have made sense based on a Victorian understanding of the world.