Picture - Outline

I think the reason your version isn't working is because all of the objects on your slide have timelines that extend to the end.

Since the Fade animation is only triggered at the end of an object's timeline, in my version, I made the line drawing's timeline end after 1 second. The button that switches to the photo also has a timeline that ends after 1 second.

To prevent the switch from happening before the user has a chance to push the Switch button, I put a cue point a 0.25 seconds and assigned a trigger to pause the timeline there. So the slide loads, runs for 0.25 seconds and then stops. The Switch button has a trigger that Resumes the timeline when the button is clicked. This lets the Fade out on the button and the line drawing proceed. With those two elements faded out, the other Switch button and the photo are revealed.

The other Switch button simply has a trigger that jumps the user back to this same slide. Since the slide is set to Reset to Initial State when revisited, it has the effect of starting the slide over again from the beginning, with the original line drawing and Switch button now on the top again.

Take a look at the timeline and the triggers panel in my original Storyline file to see the details.