s10 doesn't have any infra red iris scanner like the s9 plus. The face unlock in s10 line up is just photo identification and not that secure. Its recommend that you use fingerprint instead
You can put it in that way but the design logic for making the s10 was to have minimal bazel which makes the screen really good to enjoy video contents. if Samsung had to put and iris scanner they had to have had a notch of iPhone's size which really looks ugly. So I hope you find the logic here. But anyway as a consumer you can demand the things you want in a flagship✌✌
