Good one. You are correct. The text beside it says "OneDrive for Business notification icons signify that sync is in progress. This includes when you are uploading files, or OneDrive is syncing new files from the cloud to your PC."
I think the link I posted says something similar, but doesn't refer to One Drive - much more complicated explanation.
I don't use One drive, so, asking, referring to the ops query. Would it be normal for it to pop up on more than one instance?