By design, the remove embedded icon displays a cross sign in most of the skins. For the modern skins(such as Silk, Glow, MetroTouch, Bootstrap), we decided to use trash icon with the introduction of font icons in order to improve the look and feel of the RadButton. However, we don't plan changing the current sprite of those skins which are already using cross icon. You could use a custom icon to display a trash icon or use any of the skins which are already using such. Useful demo:

http://demos.telerik.com/aspnet-ajax/button/examples/customicons/defaultcs.aspx