Consider the molecular view of an electrochemical cell involving the overall reaction:
Zn(s) + Ni2+ (aq) → Zn2+(aq) + Ni(s)
Draw a similar sketch showing how the cell might appear after it has generated a substantial amount of electrical current.
After a substantial amount of electric current would be generated by the cell ; the sketch of the cell would show formation of an increased number of zinc ions in solution and loss of zinc atoms from the surface of the anode .
The cathode should have an increased number of nickel atoms and a corresponding decrease in the nickel ions from solution .
This will happen as per the general working of any electromagnetic cell ,where the anode metal dissolves in the solution and the cathode metals have more deposits on it from the solution .