The first piece is a dark, scary and eerie whereas the second painting has lots of bright colours and a much more happy mood. As well as this, the first piece is very tonal and more focused on grey scale than the second one, which seems more focused on colour than the tonal work.
The first painting is scary and dark due to the dark color used in the forest/trees and smoke used to created a scary mood. The second painting is joyful and happy due to the bright and vibrant colors used in the flowers and plants.