From the beginning of photos appearing on GE slips I've gotten just the top of my head; but since I return to the US from abroad 99% of the time in JFK (T8 or T4) the photo on GE slip was never an issue since CBP always asked to see pp photo anyway.
Today at JFK T4 I used a new 2.0 GE terminal and made an effort to center my face on the screen, if one is short it takes some effort, but I got it to work--no pp, no fingerprints, no questions to answer.^ The CBP agent who collected the slip did NOT ask to see pp--per Bob Dylan song "the times they are a-changing"