The really white mountains are snowy, but that may not have come across properly. I'll have a look at that. The elemental planes are actually physical planes so couldn't be a ball of fire, globe of water or similar. So the order is Air (top left), water (top right), earth (bottom right), fire (bottom left). They correspond to spring (air), summer (fire), autumn (earth) and winter (water). These planes are considered to be more representational than actual maps.

Thanks for the comments.