The Psalm, as the one before it, begins and ends with "Bless the LORD,  O my soul!" 104:1, 35.

The Psalm speaks of God's work in creation and nature. All of this is to motivate us to praise God.

The idea of pantheism is that God is to be equated with the forces of nature.  This psalm speaks of a God who is transcendent, who is far greater than the world He has made.
He is clothed in "splendor and majesty" in 104:1. He is covered in light- 104:2; I Tim. 6:15 .
He created the moon and the sun- 104:19 . The sun and moon are not worthy of worship, but are held in the hand of the God who made them.

The idea of deism is that God created the world but is not intimately involved with man and the rest of Creation. This psalm presents a God who is deeply involved in creation. He sends forth springs in the valleys (104:10 ); He causes the grass to grow (104:14 ); He plants the trees (104:16 ). Even the mightiest of beasts depends upon Him for sustenance  (104:21 , 26-27).

All of this leads us to praise God- 104:1, 24, 33, 34, 35