I don't have DI so this is a guess but shouldn't take long to test.
Click somewhere in the tool bar area.
Right click.
If you see a menu option like "Customize" click on that. <else my guess is done>
You might see a tab labeled "Toolbars" or similar.
There could be check box for "large icons". If so click in the check box and the "apply" or what ever may be in the window.