UICollectionView and MVVM

I'm trying to understand how I can use MVVM to develop a reusable UICollectionViewController.

Suppose you create a view model for each type of UICollectionViewCell

struct CollectionTestCellViewModel {
    let name: String
    let surname: String

    var identifier: String {
        return CollectionTestCell.identifier
    }

    var size: CGSize?
}

And the cell:

class CollectionTestCell: UICollectionViewCell {
    @IBOutlet weak var surnameLabel: UILabel!
    @IBOutlet weak var nameLabel: UILabel!

    func configure(with viewModel: CollectionTestCellViewModel) {
        surnameLabel.text = viewModel.surname
        nameLabel.text = viewModel.name
    }
}

In the view controller I have something like that:

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let viewModel = sections[indexPath.section][indexPath.row]
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: viewModel.identifier, for: indexPath)
    configure(view: cell, with: viewModel)
    return cell
}

So far no problem. But consider now this method of UICollectionViewDelegateFlowLayout:

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
    let viewModel = sections[indexPath.section][indexPath.row]
    return viewModel.size ?? UICollectionViewFlowLayoutAutomaticSize
}

The point is I have layout information (the size of the cell) in the view model. This allows me to put in my view controller the layout delegate methods, but I don't know if this violate the MVVM pattern.

The final question is: what should I put inside the view model (of a cell for example)? It is "allowed" to put layout data inside the view model?

Thanks