Is this an airport thing i.e. air bridge setup?

For B77W, boarding via door 3 (over wing doors) probably needs a lot of carefully maneuvering around the wing?
Even if this is doable, it's probably too risky in accidentally damaging the aircraft.

As a J pax, don't board first! Let everyone including Y pax get on before you get on.
Then nobody will be walking pass you but do wipe down your seat and everything around it before sitting down.