CollectionViewController.swift

collectionView.pasteConfiguration = UIPasteConfiguration(forAccepting: UIImage.self)

...

override func paste(itemProviders: [NSItemProvider]) {
    for provider in itemProviders {
        provider.loadObject(ofClass: UIImage.self, completionHandler: { item, error in
            guard error == nil else {
                return
            }
            DispatchQueue.main.async {
                self.viewModel.cats.append(Cat(name: "New cat", image: item as! UIImage))
                self.collectionView.reloadData()
                self.collectionView.reloadItems(at: self.collectionView.indexPathsForVisibleItems)
            }
        })
    }
}