Can someone explain how this is 4k? Apple's Thunderbolt Display has a resolution of 2560x1440 [1] and ASUS' PB287Q also has 2560x1440 according to Amazon [2].

What am I missing? UPDATE: I transposed digits and looked at the PB278Q not the PB287Q.

[1] https://www.apple.com/displays/specs.html

[2] http://www.amazon.com/PB278Q-27-Inch-LED-lit-Professional-Gr...