I downloaded \"Office 2010 Add-In: Icons Gallery\" that is docx file with two backstage tabs that hold icons.
How can I extract the icons or use them in my application?<
This is an old question, but I miss an "how to use" not "how to view" answer.
In Visual Studio 2015 you can just assign the name (or ID - shown in the docx File right below the pictures) to the "OfficeImageId" Property. This Property is for example available in Microsoft.Office.Tools.Ribbon.RibbonEditBox or .RibbonButton.