The login portlet is not displayed when the default dashboard has no portlets. Under 3.12.x it actually gives the user the link to add a portlet. Under 3.13 it actually displays nothing (check the attached screeshots). This is a large problem under 3.12.x because the login link in the header goes to the dashboard. Under 3.13 I believe the login link takes you directly to the static jsp.

Also, the width of the login portlet seems to depend upon the layout of the system dashboard. If the system dashboard has 1 column, then the portlet will take up the whole screen. When it has two columns, the login portlet only takes up half the screen (check screenshots).