Micro-fiction pieces like this one are intended to deliver a brief, intimate picture. The glimpse you've given us here is indeed intimate - we see two people in front of a fire, one practically in the lap of the other. At least one - if not both - is mourning the absence of someone named Benny. For a first piece of micro-fiction, you hit the requirements of the format nicely. Your technique and grammar is spot-on.
For future pieces, I might avoid repeating words, as you did with "cold, dark, and unreasonably depressing". Since word count is limited, it would have been nice to see those words instead directed toward setting the scene a bit more. You could even have moved the last line up to replace this one, then come up with a tighter, more emotive ending line and not have any more words than you're already using.
Thank you for the wonderfully accurate critique.
I was wondering -- I've been looking around and different places say different things -- what, for you, is the maximum word-count of a piece of micro-fiction?
I've heard it described as less than a thousand words or as little as six, like in the now-famous example: "For sale: Baby shoes, never used."
There doesn't seem to be a rule about it, in other words. But I'd start with very short ones, get good at it, then allow yourself more. First six, then twenty, then fifty, and so on. The goal is to paint a clear picture and still ignite the reader's imagination. It'll teach you to learn the economy of a well-chosen word, word order, and sentence structure.