What would be a stylistic analysis of "The Cloud" by Percy Bysshe Shelley?

It makes most sense to read this poem in iambic feet with each line of tetrameter (four feet) followed by a line of trimeter (three feet). Sometimes the trimeter lines use the trochee instead of the iamb, but that is to fit the rhythm. This causes the poem to have a singsong quality. Consider these first two lines with the stressed syllables in bold: 

I bring fresh showers for the thirsting flowers, 
From the seas and streams; 

This repetition suggests movement rather than redundancy. The singsong rhythm moves the poem along, giving the image of a cloud's fluid transience from one thing to another. 
The cloud discusses all of its functions. The constant movement implies continual change. This is a theme Shelley uses often. The cyclic nature of the cloud's functions suggests impermanence. This, in turn, is a parallel to human life, which is also characterized by continual change. 
Using "I," Shelley personifies the cloud. Since the cloud discusses its own movement and change, the poet personifies change itself. Of course, the use of personification can also be used to suggest a parallel with human lives. Reading "I" as the cloud, the reader could just as easily interpret the poem as a metaphor for human life. As much as "The Cloud" is about change in general, it is perhaps a sentiment of comfort for anyone who might fear change and/or death with lines such as "I pass through the pores of the ocean and shores; / I change, but cannot die."