Esplora readJoystickX and readJoystickY reference pages

The pages for both readJoystickX and readJoystickY show that movement up and right should return positive values, with movement down and left resulting in negative values.

But when doing the exercises and seeing the serial output, it appears to be opposite. In fact, the map function in the Esplora joystick mouse example specifically swaps the values to make the mouse move the correct horizontal direction (making positive values negative to move left, and vice versa):

Am I just missing something obvious or going crazy perhaps?