Hi and welcome to devnet,
Why are you doing all these scaling operation to, in the end, not used that scaled pixmap ?
In any case, you should start by making it work without particular scaling or fixed size. Once you have ensured that you have the icon properly working, you can start scaling the icon, and only once you are sure you have what you want, fix the size of the QLabel.
That said, why not use a QListView/QListWidget to show these icon.