This does per pixel shading, however the pixel normal is calculated from the tangent of nearby pixels, so it is effectively a plane. The difference from 3Object lighting is that the light attenuation can vary across the face of a polygon. Additionally spotlight edges can vary across the face of a polygon. Finally, you can enable procedural normals based on diffuse texture which can further vary the normal and light calculation.
I am also experimenting with adding normal map support to this effect with 3DObject, it is not yet available, but if the experiment works out, I'll add it as an option.