I don't have any of my own pictures showing what hologram swirls look like in aluminum but a quick Google search found these,
The above are from a rotary buffer. Since the pad only spins in a single direction it imparts its own unique scratch pattern.
The FLEX 3401 rotates and oscillates and as such does not leave the hologram scratch pattern unique to rotary buffers.
If you use a rotary buffer simply re-polish the aluminum using your Porter Cable and this will remove the holograms.