Proposed:

• Ditch the name "Policy1 KDE Agent" or move it to the "additional details" section. An inexperienced user might not understand what this means;
• The text is a bit repetitive. In the first sentence, is already implied that authentication is required. The whole text could be updated to something more simple, like "Authentication is required for applying changes".
• The password field could be vertical aligned like this:
  

Other ideas:

• Show the user picture and the username
• Show the name of the window which triggered the authentication dialog, to make clearer where it came from. For example, when applying changes in Muon, it shows "org.kubuntu.qaptworker3.commitchanges" instead of "Muon Package Manager".
• Thinking about the text, instead of an affirmative sentence, this dialog could show a question, because it seems to be implying that the user must at all times to accept this;
• Make the password to have an embedded label, like the one seem in SDDM, which supports the view password function (eye icon).

• Dim the screen when authentication privileges is required (by making the screen darker, it would indicate to the user that the action is critical and it would help to rethink the decision, if needed):

References:

Simple text, showing user picture, showing the view password button:

Simple text, fields vertically aligned:

Simple text, showing the program name, password label inside the field: