If no images are displayed for pages, URLs, or portlet nodes in the tree navigation view, review your mwp.properties settings.
mwp.tree.use.images=true
Also check the default tree image properties (mwp.tree.default.image.page, mwp.tree.default.image.portlet, mwp.tree.default.image.url) in mwp.properties. The default image is displayed if the Extended Properties portlet has not been used to configure another image for the page, URL, or portlet. Refer to the topic Extended Properties Portlet for more details.
See the topic Configuring properties for the Mobile Portal Accelerator extensions for details on changing properties in the mwp.properties file and how to restart the WebSphere_Portal application server after all properties have been modified.