Although with prelude repeats it is good to consider a few choice spots for ornamentation, (the amount of embellishment depends on the particular prelude, though 'just enough' is the rule of thumb ), but this particular prelude - the way it's written - the ornaments would only burden the delicacy and the laconic and striking lines of the composition. Not sure I would change any articulation either. You might try playing it the first time kind of "straight" emotionally, with absolutely no rubato. Then the second time have slightly more dynamic swells, with just a touch of rubato. And I mean just a touch. (Slightly more 'romantic').
Also, different lines (phrases) could be more highlighted (and less highlighted) than the first time.
Give it a try!