There is a challenge inherent in this deer, one that goes beyond the obvious challenge it presents. The obvious challenge, obviously, is obvious: this deer is jumping through a plate-glass window and gallivanting through a gym in Anderson, South Carolina, all of which is transparently a challenge to the people who own and operate the gym and the people who exercise in it, all of whom presumably would have preferred that the deer not do any of those things. The whole of this brief video—the deer was in the gym for two high-energy minutes, and left the way it came—is the deer issuing and making good upon that challenge.
The deer is not supposed to be there, and yet there it is. The formica tables in the front of the gym are clearly for members' use only, and yet there is the deer scrambling over them. Racks of barbells and weight benches are for storing dumbbells and lifting weights, and yet there is the deer bounding over them with the combination of pure delight and absolute soul-splitting terror unique to your dumber mammals. Its every action carries the implicit question: What are you going to do about the inconvenient fact that I, a deer, am 100 percent up in your gym flinging myself around? The closest thing there is to an answer in the video is when that one dude holding a pair of dumbbells in the weight room kind of sidesteps into the middle of the room while holding them at his sides as the deer boings around the space. It's not a very good answer, although to be fair this is also a difficult and open-ended question.
But the other challenge, the deeper one, is what to say about this. Should the deer be likened to something, or made to stand in for nature itself? This is not a stretch, as anyone who has ever encountered the dim gaze of deer standing by a country road knows how weirdly reproachful it can feel. Is it wise to pretend that the deer read the online reviews of the gym, and was moved by the praise for the frequently cleaned bathrooms, "breath taking workouts, mind blowing atmosphere, [and] very motivationalm [something]?" The deer almost certainly did not read these reviews, so, no, that's probably not wise. And yet you can't just plug in the video and let the thing go, because at that point you are adding no context or entertainment or value, no heat or light. You are saying, simply, "Here is a deer in a gym, in a small South Carolina city nearish to Greenville and Spartanburg." And anyone can see that.
What you should do, if you must write about it, is what Columbia, South Carolina TV station WLTX did. You should begin your post about the story, as they did, with the words "this deer clearly didn't skip leg day." Just do that and you'll be fine.