I just encountered this BBC article that includes an image to educate reader about different types of aircraft and the altitudes that they usually fly at.
I think that they very accidentally omitted a small detail about weather balloons that could be a bit important for a reader trying to build their own educated opinion, so I’ve added it (Source).
So…
It looks like a high altitude weather balloon, has typical hardware and sensors for a high altitude weather balloon, and is rated for the height of high altitude weather balloons?
By god! It is a spying tool!