The first section of this famous metaphysical poem relies on the personification of the drop of dew as it is given various human qualities in the initial description of this part of the poem. Of course, Marvell is building this description up so that he can introduce the central metaphor or conceit in line 19, where he compares the drop of dew to the human soul that yearns to return to heaven from where it came. Note the following example of personification in the section you have highlighted:
How it the purple flow'r does slight,
Scarce touching where it lyes,
But gazing back upon the Skies,
Shines with a mournful Light;
Like its own Tear
The drop of dew is given human qualities in the way that it is shown to "slight" the purple flower and how it is described as "gazing back" at the heavens above. Note, too, the simile that is introduced when its shining is described as being "Like its own Tear" to highlight the sadness and grief of the drop of dew. These are some examples of the way in which literary terms are used to build up the description of the drop of dew. Have another look at the poem now and see if you can find any more. Good luck!