> Also, it is interesting that they are not using deep learning for this. They are using a Discriminative Gaussian Process Latent Variable Model.

It's my understanding that deep learning is more interesting when you have a large dataset and need to generalize (e.g., recognize faces sideways, upside-down, etc), otherwise, when the requirements are more predictable, the hand-tuned algorithms tend to perform better. The task of finding whether two pictures are from the same person doesn't seem appropriate for DL (compared to e.g. find whether a picture contains a person).

Would that be correct?