While having attended two live samba shows doesn't make me an expert by any means, I have come to the conclusion that there is not one but many ways to dance samba.
My first samba experience was on a Monday night in Centro. There was a tarp held up by poles set up where 4 streets came together in a small plaza and beneath it were a group of musicians seated on folding chairs. Someone had set up shop a few feet away with big coolers full of cold drinks. People crowded around the band to hear them play samba and clapped and sang along energetically. As we moved in to listen we were befriended by the people standing around us and when we asked them to teach us how to samba each person showed us something different, from a complicated to a very simple step. One man said the women dance samba like they're squishing a cockroach with their toe while the men step on the imaginary cockroach with their heel. Everyone was moving their feet in a different manner but I think it's all considered samba if the music is.
Looking around at all the feet around me in Carioca da Gema (in Lapa) I noticed everyone was doing something different. Some people were moving their feet quickly, some slowly, some with a lot of hip and knee action, and some people were just barely shuffling their feet.
Also worth mentioning is that before heading over to Carioca da Gema we ate at a super tasty, very pricey Bahian restaurant. Bahia is a state to the north of Rio known for the particularly strong African influence in its culture. A traditional Bahian woman would dress in a white dress and wrap up her hair in a sort of white turban also, the proprietress of the restaurant we visited, Yorubá, was dressed just so. One dish consisted of cakes fried in palm oil covered with a bean paste and filled with shrimp and chopped tomatoes and onions. Another dish was a kind manioc/potato type flour boat filled with crab paste. Then we had a creamy seafood dip on a starchy vegetable. I can't remember all of the ingredients but it was delicious. Since we didn't get to make it over to Bahia I'm glad we got to sample a bit of the delicious cuisine.