My snippet has a image field. The image is not shown in snippet admin index page.

class Product(ClusterableModel):
    name = models.CharField(max_length=255)
    image = models.ForeignKey(
        "wagtailimages.Image",
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
        related_name="+",
    )
    sku = models.CharField(max_length=128)
    number = models.IntegerField()

    def schedule(self):
        return format_html("<a>First</a> | <a>Second</a>")

    panels = [
        FieldPanel("name"),
        FieldPanel("image"),
        FieldPanel("sku"),
        FieldPanel("number"),
    ]

    def __str__(self):
        return self.name

class ProductViewSet(SnippetViewSet):
    model = Product
    menu_icon = "pilcrow"  # change as required
    menu_order = 200  # will put in 3rd place (000 being 1st, 100 2nd)
    add_to_admin_menu = True  # or False to exclude your model from the menu

    search_fields = ("name", "sku")
    list_display = ("name", "sku", "image", "number", "schedule")

register_snippet(ProductViewSet)

it shows like this
example index admin page

I want to show the image itself, not the image name.