Tooth exposed under dental bridge permanently cemented 2 weeks ago. Do I have dentist send back to lab? (photos)

Sending the bridge back to the lab won't change the location of the margin. If you are concerned about the way it looks, the bridge would need to be removed, the tooth needs to be prepared more and impressions for a new bridge need to be taken. I would recommend returning to your dentist to speak with him/her about your concerns.  I hope this helps.  Follow me for more questions and answers.

The exposure appears to be the root of the tooth, meaning the gums have receded or simply the bridge edge ends above the gums.  Sending the bridge back won't change the location of the margin.  If this must be changed, the tooth needs to be prepared more and new impressions taken.

The fact that the bridge margin leaves a little tooth exposed is not a functional problem and in fact makes it easier to clean. Aesthetically, it depends on whether or not it shows when you smile. However, the only way to change the margin is to cut the bridge off and start all over. As far as the smile makeover in general, don't move forward with permanent cementation until you are completely satisfied.