Readers in VTK load only the geometry and the scalar fields.
Moreover, the animation is computed on the CPU in order to be able to connect the reader to post-processing filters, so it is very slow.
If you want to load the textures, the camera, and the lights as well, you need to use the importer.
GPU-accelerated animations will be possible in VTK 9.1 but if you need skinning and morphing support, you will have to provide a custom vertex shader to the polydata mapper.