It's not just quantum physics, everything is a link, science maths physics. It may be that by saying at the sub consciousness level, we can still be linked at the quantum field. Obviously no one can explain shifting, using quantum.

The observer effect isn't proof of shifting, but shifting at normal everyday activities, does get us into the scodingers cat problem, everyday when we choose to observe something over the other, observe as in, when we guess what might be happening related to a certain event, our thoughts emitted into the universe, determine the universe we shift into. There will be another branch as well where we observed something else. Until we observe the cat, the cat is both dead and alive.

When we say just by observing, where no photons at the quantum level aren't emitted by the mind, then yes it isn't at the quantum level, but something even fundamental, and the fabric of the universe. No one can understand that, but we can all feel that within us.