Not sure why you are writing logic here.

The idea of *Widget files is that they only contain GUI elements and GUI elements related to that GUI.

talkeditor.py is where all the logic should go. create_presentation() is logic so you should no be including this in the view.

The reason is someone in the future maybe not this file specifically but maybe  they want to reuse your widget for something else. They don't want any of your logic with it though because perhaps their specialized widget does something different but it's possible to reuse the view.