If not mistaken, any picture you download from whatsapp automatically will save to your whatsapp folder and will be available in the gallery folder with the name "Whatsapp Image"
Every photos that you receive and can view is automatically saved in your phone. Just go to "Gallery" apps, go to "Albums" tab, scroll down to folder "Whatsapp Images".
As long as you turn on media visibility like Sy3ney commented above. You should be able see it.
