Pet peeve alert: That's a fir (or maybe a spruce), not a pine. This is a pine
In any case though, it's still symmetrical. I meant the tree that's not a silhouette, that one was fine. I meant the dithered one that is literally symmetrical, down to the pixel level. The two silhouette trees were fine. Sorry for being unclear before!
Single pixels might sometimes be unavoidable, but noise is always avoidable. If you have pixels that don't read like anything, that's noise, and it doesn't belong. Pixels that read as texture or details are not noise. However, for that to happen, they need context, larger clusters of pixels establishing the context to which those single pixels add texture/detail. If everything is detail, then there's no form, and therefore it doesn't read.
Here's an edit illustrating some of what I said in my earlier post, using solid areas of black and white to show the form:
I didn't use any dithering because I feel it's unnecessary at this size, but that's not to say you can't or shouldn't.
I also made that one dithered tree asymmetrical while I was at it.