ImageModel.cs

namespace ImageFilePickerSample.Models
{
    public class ImageModel : INotifyPropertyChanged
    {
        public ObservableCollection<TItem> Items { get; set; } = new ObservableCollection<TItem>();

        public ImageModel()
        {
            for (var index = 0; index < 10; index++)
            {
                this.Items.Add(new TItem() { ID = new Guid(), });
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;
        protected virtual void OnPropertyChanged([CallerMemberName] String propertyName = "")
        {
            this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}