If the tech didn't say anything then don't worry. She would notice if your babies nose was missing. Ultrasounds are images produced by the light off of objects. It's not easy to see everything or get a good picture of everything
Are they worried? if not, try not to stress too much, my last US was at 22 weeks and lil miss wouldn't show us her face (been like that at every US so far lol) they could only see one eye because she wouldn't turn her head to see the rest...they are not worried.