The contrasts are clear - between the street food experiences my mother and I had on my recent South Korea vacation and the one before (in 2009), and also between that on this recent trip and what we had in Vietnam last year.
For a start, while we saw some interesting food being sold on the streets of Hanoi, we ended up feasting on them only with our eyes. It wasn't that the food didn't look yummy -- but, rather, that the dining conditions didn't come across as all that ideal to us.
Specifically, Vietnamese street food tends to be consumed while seated on low stools (as opposed to chairs) and using other stools like tables; and thereby resulting in both the food and the diner being much closer to the frequently super dusty ground than I'd like. Also, consider this as a quirk of mine but I like to drink (not necessarily something alcoholic but definitely cool and liquid!) when I eat while the Vietnamese seem to look upon eating and drinking as separate affairs!
On the Korean front: for some reason, my mother and I didn't spot as many street food stalls on our previous visit to the country as we did this time around! So whereas I can only recall buying and eating street food on one occasion in 2009, it pretty much became an evening ritual on this recent vacation to wander around the streets near our hotel and sample some of the wide variety of food being hawked on the streets!
Among the offerings I tried from the stall in the top-most photo was that which consisted of a large Western-style sausage with a fish cake and dark green-colored nori (seaweed) wrapping! While I've eaten all three of those things before, I never had them in the same bite before -- and while the taste contrasts in my mouth were initially quite disconcerting, once I got used to it, I decided that this was one yummy savory snack and would not be averse to having it again! ;b