Testing control surfaces pre flight; what feedback does pilot recieve?
According to this PDF from Airbus (see section "The importance of the pre-flight, flight controls check"), the PF (pilot flying) moves the sidestick around in a defined manner while the PNF (pilot not flying) watches the ECAM F/CTL (flight control) page and calls out "full up", "full down", etc. (Actually the procedure is described in the A330 SOP but the linked document explains it in a comprehensible fashion.)



Source

The ECAM F/CTL page displays the actual position of the control surfaces. This video from Captain Joe explains the behaviour of the sidestick in an Airbus and shows how the control surfaces can be checked on the ECAM F/CTL page (from approx. 1:40 to 2:15).