This is a very good question which I asked myself a few times as well - and I am curious of the answers (I do the same in France). Now, I am French and it took me quite some time and hand waving to understand how you manage to make the turn with just these two arrows (not to mention that we drive on the other side as in the UK and Australia). My wife was watching me with curiosity when my hands were doing the maneuvres. —
WoJ 1 min ago