The two human figures represent a couple, probably gay, who are happy and free.  They even defy gravity.

The figures are all at different angles and this is a visual pun that says explicitly that sexual orientation doesn't matter.

The dog is another symbol of sweet innocence.  It is part of the family.  It is this painting's radiant baby.

The house is where the family lives.  The family is quite ordinary and traditional in many ways.

The house is even surrounded by a traditional picket fence.  A mailbox is their connection with the outside world.

There is a fireplace and smoke comes out of the chimney to show domestic contentment

The flowers and the trees represent our oneness with nature.

The bluebird represents the infinite freedom inherent in human nature—no matter who you are.

The blue sky and the bright yellow sun tell us that life is good.

Rays come out of the sun to represent the freshness and sweetness of all creation.