If you have created a front panel covering your shelves, such as a glass door on a cooler, you will not be able to select any products behind the front panel. In such case you can use this command to toggle the visibility of all front panels. Hiding front panels lets you select and edit products behind the panels. You can then display the front panels again once your planogram is ready to publish.
Tip: this command is also available in the Context menu > Display.