Thanks for the feedback.

The point is:

- you have a qubit in position |1>

- if you first apply the Hadamard gate it it jumps to |->

- a following Z-gate flips |-> to |+>

But if you first apply the Z-gate on |1> it remains in |1> but its phase flips

- the following Hadamard gate puts it into |-> (but the minus sign appears on the |0> part of the equation. But it is still |->