I was going to post this in response to something Jen said in her scrap, but it turned pretty soap-boxy, so I decided to find my own soap box
What she said about how reviewing is a different kind of writing reminded me of a distinction I noticed some time ago. In a post, or any kind of telling of a story really, it's the difference between reporting what happened, and pulling the writer/reader/character into the moment, almost feeling it as it's happening. Veterans of the writing trade may know this as the distinction between 'tell' and 'show' respectively.
According to conventional wisdom and English teachers, you're supposed to always "show don't tell". (These are the same people who tell you never to use passive voice.) But after a while, that kind of writing can be exhausting. It requires a significant amount of emotional energy. Sometimes this energy flows more easily, if the writer's in the right mood, or their empathy happens to be in alignment with the character (I suspect this is what people refer to when they claim they have the "muse").
But the problem with the "show" kind of writing, at least when taken to extremes, is one of pacing. If you have to listen to a character's every moment in excruciating detail, the story would never go anywhere. You need "tell" writing sometimes to move the plot forward. (Ex. "Then the dinner party broke up and everyone went home." The alternative is listing everyone's departure individually, as well as describing the various emotional ramifications and subtle social dynamics of each.)
You also need it to deal with minor NPCs, because there's a limit to how many characters a writer can actualize in her brain at once. It's fairly simple to 'tell' in a general sense what a character might say, but once you start trying to come up with actual dialogue, suddenly you're 'in the moment', and you have to craft a voice and possibly an entire personality for this person. There are so many subtle variations to how a person might say a thing, and sometimes, for minor one-note characters, it's just not worth putting that much life into them.
The other note I wanted to leave here was some advice for new writers, or people who struggle to write. "Tell" writing is super useful, especially when you feel your muse has fled (see my writer's block post for more insights). It might not be what people call "good" writing, but trust me, when you're posting buddy is waiting for a post that you just aren't inspired for, it's a lost easier to just report in a possibly boring way what your character is doing, than to try to summon the special mind state that brings you into the moment. Much as I'm sure your buddy loves to read your delightful prose, what they are really looking for is something that they can respond to, because they want to write good stuff too! Also, if you're lucky, sometimes that 'tell' writing is just what you need to get you over the hump of a particularly uninteresting scene, and once you're through, floodgates of the exceptionally good writing might open back up, the "muse" returning full force. But you have to get there first