Why would an atom emit virtual photons instead of nonvirtual photons?

Question

Why would an atom emit virtual photons instead of nonvirtual photons?

Answer 1

An atom can only emit real photons if it makes a transition between energy levels, and the energy goes into a photon.

Any charged particle emits and reabsorbs virtual photons.  If there's another charged particle in the vicinity, it can absorb the virtual photon instead, which leads to the electromagnetic force between charges.