Different step depths existing outdoor stairs

[juancarlos]

Have an existing outdoor wooden staircase to which we are going to add a railing. I have noticed that the first step from the top is deeper than the others and am considering adjusting it by moving the metal frame under the steps.
But my question is more out of curiosity if anyone knows why the frame for the first step is deeper? All steps in such a short staircase should have the same depth, right? See pictures.

 

[Centano]

Probably intended to be the first step and not as in your case the second step.

 

[juancarlos]

Of course, thank you!