this is happing because the feature points to a plugin that does not contain branding logic/content, such as about.html, jboss_about.png, about.properties, about.ini,etc.
see http://pookzilla.net/wp/2006/01/how-can-i-give-my-eclipse-blob-icon-in/ and http://www.ibm.com/developerworks/opensource/library/os-ecfeat/index.html