You are probably right, ah-chanh. After I posted this, I actually realized there's something similar on the screen of the copier where I work. It shows you whether you're at the copy, fax, or scan screen.
However, the copier is consistent and clear. I can't say that about the K900. I've pushed most everything and I can't get those dots to act in any way that seems to convey any info. It just seems to be random. There must be some sense to it, but I can't see it.
2016 V8 VIP+, black with white interior