A physical mark can be forced on you so it is not physical. It is the metaphorical one in which you give up and go along with the world on homosexuality, euthanasia, abortion or you name it that you have voluntarily accepted the mark in order to buy or sell. Perhaps to access your bank account or get employment or social security that you have to sign a contract agreeing to their terms of "human rights and progress" to be processed.
Yes, a physical mark CAN be forced on you. WILL it be forced on us? No, God won't allow it to be forced. It MUST be accepted/voluntary. But I believe it WILL BE physical. It won't, however, be forced. That's the niftiness of it. Yes, it's a physical mark. No, you are not mandated to accept it. But if you DON'T accept it, you won't work. You won't be able to buy food. You won't be able to bank. Etc. It WILL be a physical mark. It won't be forced.