The Fluid Display touts an "exclusive optimization solution" that reportedly renders frames 7 percent faster, and it boasts a 240Hz touch sampling rate to make it that much more responsive to your finger taps. You can also expect smoother-looking video playback at 60Hz or 120Hz, too, thanks to the same kind of frame insertion technology used in many modern TVs (this comes at the same time as TV makers are courting people who hate motion smoothing, but never you mind that).
You can likewise expect better color accuracy through "professional tuning" that promises a Just Noticeable Color Difference ratio of less than 0.8 (slightly better than the Galaxy S10's 0.9, for context), 10-bit color that's automatically calibrated at the factory and a 1,000-nit peak brightness.
We wouldn't be surprised if 120Hz AMOLED displays appear in more phones in 2020 (Apple and Samsung are rumored to be making that leap). What OnePlus claims to be special now may be relatively commonplace by the end of the year. Still, the Fluid Display shows that very fast refresh rates are coming to mainstream phones before long, and sets a benchmark for what to expect.