Futura superba vs Laurentii, how to tell the difference?

One was sold as Futura superba and one as Laurentii, and however much I look at them and google what differences there are supposed to be between the two I just can't see it! I have this issue with comparison pictures online too fwiw. I dont see either as being taller/shorter or haveing wider/slimmer leaves. I understand it can be a maturity-issue but still, I just can't see it 🤨 any pointers??

One was sold as Futura superba and one as Laurentii, and however much I look at them and google what differences there are supposed to be between the two I just can't see it! I have this issue with comparison pictures online too fwiw. I dont see either as being taller/shorter or haveing wider/slimmer leaves. I understand it can be a maturity-issue but still, I just can't see it 🤨 any pointers??