If you create a chart using Family Tree Builder software:
Click on the 'Options button' above the chart view. In the window that opens you can use various tabs to edit the chart look according to your preferences.
First click on the Design tab and select 'Traditional'.
Then click on the 'General' tab and under 'Personal Photos' change the section 'Show Personal Photos' to 'Only if Exist' or 'Never'.
Click 'OK' to save changes.
If you create a chart on your family site online:
Click on the ‘Advanced customization options’, to choose from the advanced editing options available for your chart.
There you can select either 'Do not show personal photos' or 'Only if exists' option under 'Photos'.
You can also select a different chart style (17 or 18), as described here: How can I edit the chart style?