Sorry to dig up an old thread, but it seems that the phones affected by the brightness issues in 10.2.1 were the 6, 6 Plus, 6s, 6s Plus, and SE — all the models that Apple stated that they throttled in 10.2.1…I wonder if we were seeing the very first steps of that? I know people have a lot of opinions one way or another about how it was handled and what Apple is doing, but it sort of ties up an almost year-long mystery for that "bug"