It's from outside our solar system in origin, so I'd say we are not 100% in predicting what to expect, more so when we still can't get weather forecasts 100% right and get unexpected weather events.
Having gone thru the other `interpretations of observations`, I'd probably not of been as quick to lean down that path of aliens. Indeed, whilst it is unusual, comparing it to the known and as such, objects originating in our solar system will see conflicts like orbit, speed, direction, shape and composition. I'd also say it's strange shape would play more a factor in the variance of how light is reflected back and be more logical an explanation of its variance from the `norm`.
Besides, for all we know, `aliens` may view a lifeform like us in the same way we view bacteria. So the question would be, if Aliens found us - would they care.
But is this an alien probe - I'm sure many would love it to be so, but as it stands, feels a bit too reaching from what I read. [EDIT type o's]