It is OK to Add an Explanation
Above there's already a contradicting answer. Originally, I was posting this as a comment. Decided to submit my own answer and let the community decide:
While there are subtleties that may be missed, I feel strongly that some explanation is better than no explanation. I'd hope we'd all prefer to live in a CGCC populated with well-explained answers and minimal code-only answers.
Since we already have a consensus on code-only answers being low-quality and undesirable, it seems to post an answer without one is to implicitly give permission to the community to add it.
Fine Print
An explanation may not be edited, one must comment to correct. That would assume better knowledge, risk losing the aforementioned 'subtleties' and require the edit's approver to know the language.
If they add a note along the lines of Will add explanation, usually waiting to see if it garners attention before slaving away, one shouldn't edit until 3 days have passed since they posted.
Note
I'm trying this out generally. However, I can see the case for conventional & verbose languages like C/Python/Ruby/Haskell, as there's far greater ambiguity with those.
If downvoted into oblivion, I will post another answer specifically for terse, SBCS (usually golf) languages like APL/05AB1E/CJam as that seems far less controversial. For example, given /⍨⍳4 → 1223334444 adding:
⍳4 ⍝ Integers 1..4
⍨ ⍝ Duplicate argument on each side
/ ⍝ Replicate each element `n` times
- 2.2k
- 8
- 9