Upper blepharoplasty too conservative? (photos)

It's too early to judge. There is still considerable swelling in the upper lid, so it might look heavier now than the final result will actually be. 

Thanks for the photo and question.  It would have been great to see a 'before' photo, to compare.  You should wait a few weeks, for any residual swelling to settle, before making a final judgement about the outcome.   

Your photo exhibits bilateral upper eyelid ptosis.  Either the ptosis is caused by upper eyelid swelling related to your surgery 3 weeks ago or it existed prior to this surgery.  If it was caused by the surgery it is either temporary or permanent.  Swelling of the tissue does contribute to upper eyelid heaviness that resolves with time.  On the other hand, upper blepharoplasty can injure the levator aponeurosis, the tendon of the upper eyelid.  It can easily be severed with the skin excision.  This is generally very well tolerated.  However, for some, this causes persistent upper eyelid ptosis.  Time is what you need.  Generally it is advisable to be patient and wait 6 months before looking into revisional surgery.