A rod of Cobalt-60, a highly radioactive isotope. There's a reason it says on the side "Drop & run". Its radioactivity is the reason it's messing up the photo- as the energetic radiation strikes the cells in the phone camera, it causes those cells to light up.

It's part of this Analog Horror video by Gooseworx: https://www.youtube.com/watch?v=Td2x8s9GZlo

It's worth a watch if you can take analog horror.

My most recent game was a Hive Mind. I think I assimilated some 75% of the galaxy, getting right to the endgame crisis before the most recent update dropped. I've kind of lost interest in the save, partially because I played with Gigastructural Engineering and that updated with Machine Age as I was playing, so the save file is a little borked. Looking forward to playing with the Cosmic Storms and the upcoming Grand Archive, though.

I think I crushed two Fanatic Purifiers and assimilated the Great Khan, so you're welcome, the rest of the galaxy.

There is somewhat of a case to be made for Materialist, considering Cosmogenesis and the Synaptic Lathe. But obviously not every materialist empire goes into that. To be a fanatic purifier, you need to be Fanatically Xenophobic and either Militarist or Spiritualist. I'd expect Xenophobic empires to not care (or care significantly less), but the other two ethics are a little more debatably nebulous as to how much they'd care.