According to multiple reports online, a rare glitch with Battlefield 1’s dynamic resolution causes the quality to dip all the way down to 160 x 90.
A video posted below briefly explains the bug in question. Testing the game on a technical level, what the commentators found ended up being a low dip in resolution. The video also shows the game running at inconsistent framerates, randomly jumping from 40 FPS to 60 throughout.
Dynamic resolution is when a game offers a shifting resolution, instead of one consistent one. As different objects come into view, the resolution changes. The result is often a higher framerate, without sacrificing much graphical fidelity when done right.
The bug is rare and seems to only happen on the PlayStation 4 version of the game so far. A patch will likely follow this discovery and bring the game to a more modern resolution by it's release on October 18.