Why does wallpaper in portrait change to landscape?

[Ku Zukhairi]

wallpaper in portrait change to landscape.

I've been facing with these problem to apply portrait pictures as wallpaper in whatsapp, as its suddenly changed to landscape view. any advise from anybody? and another big let down is, when my mate sends any picture using whatsapp, its automatically saves into the gallery and its quite annoying for me when i have to delete a lots of pictures from whatsapp gallery daily. Please help.