Why why why ???

QED showed that reflection never involves photons bouncing off mirrors. Instead, the photons are absorbed by electrons of atoms in the glass and, an instant later, these electrons emit new photons. In that instant, the electrons have moved around the atom a little, and so the new photons are emitted in a new direction.

Hai..... (sigh), so confusing! So these light photons are absorbed by the electrons, and therefore when energy is absorbed, the electrons gain energy and therefore they will move to the outer shells of the atom. But, why at an instant later, these electrons will emit new photons????? And I can't visualise the last statement, and how can I link it to the law that incident angle = reflected angle???

Oh, and is there an answer to why the law of reflection states that reflected angle must = incident angle? And is there an answer to why mass attracts mass?