The palette view under the color wheel is really just another way to look at the selected wheel colors. Each column is a different hue and the rows show the different levels of saturation, or in some cases brightness, for that hue.
By default it starts at the lowest hue (>= 0°) and ends at the hue with the largest angle (< 360°). That can be a problem when the masked colors are around the 0° hue, on the red and violet zone, because that will cause the palette to be split with a cluster of hues at the start of the table and another one at the end.
In order solve this I've included a way to rotate the palette. Just pan it to the right or left and the colors will move according, allowing you to look at them grouped together. If you want to return to the default palette position a double tap on it will do it.