1. Each eye sees the object from a different angle.
2. Both eyes see the object from a different angle when the object is moved relative to your head.
The 3DS does only #1. TFA does only #2. Presumably if you did both, you could get a much stronger effect.
I think the New 3DS had the hardware to do both in theory, but it probably would have made development and backwards compatibility overly complicated!
1. Each eye sees the object from a different angle.
2. Both eyes see the object from a different angle when the object is moved relative to your head.
The 3DS does only #1. TFA does only #2. Presumably if you did both, you could get a much stronger effect.
I think the New 3DS had the hardware to do both in theory, but it probably would have made development and backwards compatibility overly complicated!