There are a number of reports that say—surprise!—a 2D image sensor can be fooled by a 2D image. The Verge was able to unlock the device with a video, and YouTube channel Unbox Therapy was able to unlock the S10 just by playing one of its public channel videos in view of the camera. The worst example is probably from AndroidWorld.it, which was able to unlock the Galaxy S10 by waving a still photo around in front of the device.
The Galaxy S10 can also reportedly have trouble telling different people apart. Security Researcher Jane Wong was able to unlock her brother’s phone with her face.