The visual representation of a signed document is a bit ugly.
The biggest issue is how it should look, which options we might want to make user configurable and such.
See also https://bugs.kde.org/show_bug.cgi?id=443403 and https://bugs.kde.org/show_bug.cgi?id=474222, https://bugs.kde.org/show_bug.cgi?id=473433 for more examples and more reports.