Recently, I wrote a review that discussed certain points in the OP's code, but did not contain any code in the review itself.
Are answers like these discouraged?
I've more or less said this before in a different context, please forgive me that I'm too lazy to go find the link right now.
No. These answers are not discouraged.
Answers are under no obligation what so ever to contain any code at all. Some great reviews have been given that fall under this category. However, keep in mind that a snippet or two of the right, or an alternative, way to do something could be worth its weight in gold to an OP. Therefore, it could be the difference between a good answer and a great answer.
This structure isn't immutable. Fix that.
This structure isn't immutable. Here's how you go about fixing that...
Which of these two answers is more valuable? Obviously the latter, but why? Well, the first answer is likely only valuable for OP, while the second becomes a long term resource for anyone coming across this question later. Also, many of us are here to teach, not simply point out flaws in other people's code like some ego-sadistical [insert your favorite slur here].
Are answers without code to be discouraged?
Are answers with code to be encouraged?
Absolutely not! Only questions are required to have embedded code. If you can still provide good information even without any code snippets, then there are no problems with your review.
As a matter of fact, one of my top answers mostly consists of paragraphs and no code snippets. Ultimately, you may decide what kind of review the question may need.
You're reviewing code, commenting on OP's practices and telling them what's good, bad, or ugly about the code being reviewed.
You can do that from your smartphone if you want - and trust me when I say phone posts are painful when code blocks get involved (although not impossible).