MT vocalizes Proverbs 31:21 as:
לֹא־תִירָ֣א לְבֵיתָ֣הּ מִשָּׁ֑לֶג כִּ֥י כָל־בֵּ֜יתָ֗הּ לָבֻ֥שׁ שָׁנִֽים׃
"She is not afraid of snow for her house, because all of her house is clothed in scarlet."
"Scarlet" here is שָׁנִים shanim.
But the LXX and Vulgate understand the same consonants differently.
The LXX reads it as the number "two" שְׁנַיִם shnayim and attaches it to the "coverings" at the beginning of the next verse: δισσὰς χλαίνας ἐποίησεν "she makes two coverings."
The Vulgate also reads it as the number "two" שְׁנַיִם shnayim, but it includes it at the end of verse 21: omnes enim domestici eius vestiti duplicibus "for her whole house is doubly clothed." The NEB and NLT agree with the Vulgate in reading "two garments" or "warm clothes."
The difference between the readings is one of interpretation of the same consonantal text, but the reason I bring it up is that the note in the NET Bible that tries to use a text-critical principle to resolve an exegetical problem. The NET Bible note says that the reading of the numeral "two" is the "easier reading and therefore suspect." The note is alluding to the often-abused text-critical canon of lectio difficilior potior, or "the more difficult reading is superior." While there is nothing wrong with the principle in general, wrongly applied it can lead scholars in the wrong direction. In particular, the NET Bible is using the principle to determine the correct vocalization of an ambiguous consonantal text. But the question of vocalization is not properly a text-critical decision, and it is questionable whether the text-critical principle preferring the more difficult reading can be made to apply in these situations.
The vocalization of the Hebrew text was not indicated in the original texts of Scripture (with the possible exception of original vowel letters). This means that many passages of Scripture, even when the consonantal text is agreed upon, are ambiguous and allow for multiple readings. The readings one chooses, then, are actually exegetical decisions rather than textual ones. In exegesis, I question whether the lectio difficilior canon is applicable. What it is essentially saying is that the most difficult interpretation is likely correct. Thus, the numeral "two" cannot be correct, because it fits too neatly into the context and practically begs to be read. But in exegesis, contextual suitability is the primary canon. What exegete in his right mind would look for the most unlikely, hard-to-understand, stretched, contextually unsuitable interpretation? Vocalizations should be chosen based on which reading best fits in the context, not based on which one makes the least sense! This kind of thinking only makes sense if the vocalization of MT is assumed to be original and authoritative and alternative readings are seen as secondary corruptions of the MT. This is a methodologically flawed approach. In reality, the consonantal text is vocalically ambiguous and requires independent interpretive disambiguation by the reader.
So when determining which reading to read for שנים, we need to look at which fits the context best. In favor of the reading "two," we have the immediate context of the verse and common sense, which says doubling up garments is more fitting for keeping warm in snow than putting on extravagant scarlet garments. In favor of the reading "scarlet," we have in the next verse a reference to the extravagance of the woman's fine linen and purple clothes and the possibility of a somewhat stretched metaphor of scarlet clothing = richness and abundance of clothing = warmth. At first glance, it seems to me like the numeral "two" may actually be the better interpretation, but either way, the point is that the exegetical question must be resolved by appeal to the best fit in context, not the worst fit.