在ListBox中加载图像列表。 WPF和MVVM

I'm trying to show a set of pictures from a directory in a ListBox. This ListBox should be updated when I select another directory. The following code does not work correcty and I don't know why. LoadImages() works correctly because _selectedImageList has the elements contained in the selected directory but the ListBox does not show anything.I'm trying to show a set of pictures from a dir