The model statement dictates what gets displayed. To use the bar-graph interface lick the mouse at any point along the centerline of a bar, and the value of that parameter will be changed to that number. You may also drag the end of a bar with the mouse. Below each set of bars is a numerical scale. If the range of that scale is not to your liking, click at any point along that scale and drag to a new position for that scale value.
Scales are always updated to make room for all the values in a set.
The bottom section has bar graphs for effect size and power. There are potentially several tests, with different powers. So, for example, tests of interactions are less powerful than tests of main effects, all other things being equal. Often, sample size is limited by time or budget. For a random effect, the effect size, squared, is thus the variance component for that term.