Helpo de LibreOffice 24.8
Displays the available icons in LibreOffice. To replace the icon that you selected in the Customize dialog, click an icon, then click the OK button.
Adds new icons to the list of icons. You see the Open dialog that imports the selected icon or icons into the internal icon directory of LibreOffice.
You can only import icons that are in the PNG file format and that are 16 × 16 or 24 × 24 pixels in size.
Click to remove the selected icon from the list. Only user-defined icons can be removed.