This is in model instance which implements the proper `DP` interface. Therefore, and taking into account hour long discussion yesterday, I believe its dimensions, given that the `PCAModel` was obtained from `PointClouds` (shape model) should be `n_points x n_dims x n_params`, i.e.

    # note the transpose
    self._d_dp.T.reshape(-1, self.template_instance.n_dims, self.n_active_components)

I'm struggling to figure out if that makes sense if the `PCAModel` was learned from `Images`. I really cannot really make sense of it right now. We can have a chat tomorrow about this...