Click Box and line styles . The Box, Border, and Line Options dialog appears.
You can change the box style separately for the different elements in the chart: Females, Males, Unknown gender, Pictures and Captions.
Select the element you want to change, then select the Border, Fill, and Shadow color you want.
Depending on the Layout you selected in the Information Pane, you will see Poster layout initial box size or Book layout maximums. Poster layout and Book layout are not tied to the specific elements but are general to the chart.
Specify the initial or maximum sizes for the boxes.
Select the line color, thickness, and line style you want for the chart border.
Select the Background color you want for the chart.
When you have finished, click OK."
you do NOT see anything about the ability to have different size boxes, depending on the about of text in them. You can control the initial or maximum sizes of the boxes, but there is nothing there for a setting for different sized based on the amount of data.
I checked and what I saw is reflected in this help menu item.