This setting was once removed, so is there anything that can be reused from the code that was removed?

This might be obvious but the expanded input field also needs to be more visible than in the image above 😄

Displaying the input field on focus is not a good option, what if the person is trying to navigate past the search icon instead of opening it. It should only expand on explicit user action like pressing the button.

Oh my this little feature has a lot of options.

One nice addition would be the ability to show only the icon.

I think this is going to be very popular and useful, however I think that finding a balance in how it happens is important.

@carolinan when you say this:

It should only expand on explicit user action like pressing the button.

Do you mean when clicking the icon? I can see that sort of working where you click the icon and it expands but the issue is clicking is also meant to 'perform the search' so there's a bit of 'double duty' going on for the interaction.

So there needs to be two buttons, one to open the "modal" that displays the input field, and one to submit.
This would also be true if the input field was opened on focus.

Just noting for anyone looking to pick this up that there was a PR for this - #31719, and it might be a good starting point for anyone looking to contribute.

A request to have an icon-only search option came in via the forums:

https://wordpress.org/support/topic/search-block-options/

This would be a great enhancement.