WhatsApp Storage access

i currently did not give WhatsApp access to my phones storage or camera roll. Although I’m not able to see pics and documents shared through WhatsApp on the device . Still I can see them in WhatsApp chat pages . Where are these files stored? ( WhatsApp servers? .No ) even with mobile data switched off I can view those pics . So ultimately I assume it is stored in the device . So where is it stored and why can’t I access it !!?