Hi Rose,
actually, the two “products” gift wrapping big and small are set to “hidden in the product catalogue” (see screenshot: https://drive.google.com/file/d/1_p4A0bV5FE2ivxU-brHMtLjYyrvT-g-r/view?usp=sharing).
As you can see on the main shop page (categories with images) and in its sidebar the category “Geschenkverpackung” (gift wrapping) is hidden because there are no products to be shown.
Storefront doesn’t seem to provide this filter categories in the sidebar. So I cannot check this…