By default, main toolbar shows all application tools and options (Figure 1). However, you can customize it going to Setup > Customize Toolbar, then enable the options that you want to display on your toolbar (Figure 2).
Click this icon to open a dialog where you can configure a printer for proofing. Proofing allows you to configure a printer so that it will copy the settings from another printer and print using those settings. This allows you to test a print in a more cost efficient way. For more information, see Proofing.