Q: Why is my video sideways?
Big Art Mob cannot rotate video so it is best to shoot video on your phone in landscape (not portrait) orientation.
If you want to shoot something in portrait, you will need some software to turn it round. You can get such software for free, there is a list here.
You can rotate still images/photos in Big Art Mob in the Edit mode (i.e. click Edit link below the image, just under Rating).