If you wish to minimize a particular Notezilla sticky note, you can click on the Roll Up icon in the note toolbar. You can Roll Down the note again to it's previously set size anytime when you need to access it.
To roll down a sticky note, click on the Roll Down icon in the Note Toolbar. A faster way to roll up/down a note is to use the shortcut key Ctrl+O from the note.
This video will show you how to do this:
To make this faster, you can associate an hotkey with this functionality.
To add an hotkey, Go to Notezilla Preferences and click on "Hotkey Tab". To access Notezilla 's Preferences, right click on Notezilla icon and choose Preferences from the menu.
Currently it is not possible to shrink sticky notes.