How to change the screen resolution of a Mac OS X Snow Leopard 10.6 guest machine?

Question

virtual box

Components:
- Main OS: Ubuntu 16.04.1 LTS;
- Software for virtualization: Virtualbox 5.1.12;
- Virtual OS: Mac OS X Snow Leopard 10.6;
Task:
Set the screen resolution to 1280x1024x32 on a Mac OS X Snow Leopard 10.6 guest machine.
There have been attempts to modify the <virtual-machine-name>.vbox-prev file using the ExtraData augmentation method.
But as I understand it, this is possible only through the installation of "guest OS add-ons" on a virtual system.