Icon Display Mode

When building a Python Add-on, how to implement the icon for each function plugin is a large icon display, just like the four options in the Manipulation group.

The command icons I made now are all like the distribution in Clipboard.

I don’t remember if the row size is hardcoded for Python add-on, but a row size of like 3 for the menu item would do the trick. I know you can do that with .NET API. Is there anything in the API reference about menu item grid size? There might be a keyword argument available, but others know best.