@Stangdon's comment is, I think, the core of the right answer.
"Skin" in English can be either a countable or a non-countable noun.
As a countable noun, "one skin", "two skins", etc, it refers to the hide of an animal, after the animal has been killed and the hide removed from the body. Like, "He kept two bear skins hanging on the wall as hunting trophies." (You could talk about the skin of a human being, of course, if you killed someone and made a rug out of his skin. But that's getting kind of creepy.)
As a non-countable noun, "skin" refers to the thing in general, of a creature living or dead. You can say, "Bob has white skin." You wouldn't say, "Bob has A white skin", just "has white skin". It's not countable.
"Vietnamese girls like white skin" is ambiguous without context. It could mean that they like their own skin to be white, or that they like men with white skin. I'm guessing you mean the second. If so, you could also say, "Vietnamese girls like men with white skin". Note that "men" here is plural, because "man" is a countable noun. ("Man" can also be uncountable, if you are talking about the human race, like "Man has written history going back several thousand years." But here we're talking about individual male people.) So "men" is plural, but "skin" is uncountable, neither singular nor plural.
It's something of an internet meme. There's a picture that's popular of a skeleton playing a trumpet. Because trumpets (in a very vague sense) make something of a 'doot' noise, people started referring to the meme by using variations on 'doot'. Some of these are 'updoot' (a variation of 'upvote') or 'doot doot mr. skeltal'.
Best Answer
While "comb" might be used by banana farmers, and could be used in some locations, it is not common. (This native speaker had never heard the expression)
A bunch of bananas is the common general phrase.
Others which seem understandable to me are "a hand of bananas" (for a bunch that is rather smaller than the comb in your picture) With about five bananas, a hand of bananas is the size that is commonly sold in supermarkets. I wouldn't have a particular word for the whole stem of bananas in the top picture, as bananas are not generally available in such large amounts. (Though "stem of bananas" would seem to make sense, I've just made that up)
So use "bunch" but you might occasionally hear "hand" or even "comb".