The cell shown in your PDF document is a Galvanic cell. It converts chemical to electrical energy by means of redox reactions and yes, electron transfer. The inert electrodes are named according to their environments and their nature themselves. The right (-) electrode is the anode because iron has a greater electrode potential (ability to oxidize). Analogously, the left (+) cathode is the cathode. The electrode with a better oxidizing ability is the one in whose vicinity oxidation occurs.
If we take A to be the anode and C the cathode, then:
The rule of thumb with reduction-oxidation reactions is: A substance can be reduced if and only if another substance is oxidized. Therefore, to answer your question, YES!, two electrons are released, but, from two respective bivalent iron cations. Therefore we find the "common denominator" and balance the amount of electrons released and absorbed.
Then, in the sum equation, the electrons cancel each other out:
Hope I helped!
Just remember: A substance can reduce only if it has the electrons to do so. You should always check if your stoichiometric coefficients are in alignment.
EDIT: By the way! Iron can never exist as because the ionization energy to expel a fourth electron (one that is not in its valence shell) is immeasurably high. So iron will always exist as either , with one valence electron, or , without any at all.