Featured image

I thought the Blog Page Header would appear above all blog posts, as on the Index blog page.

and that i would have :
a wider Blog Post Header image,
and a Featured image above the content,
the same way as it does on the blog index page

But actually, no. The Blog Page Header only appears above the blog index page. Right?

I understood that i can fix the featured image position within the Customising page

Maybe I might add the Blog Page Header abov all blog post with a hook?

Yup that's correct Blog Page Header is for the main blog page only.

You can use hook that applies to all posts like this:

<?php if ( is_single() ) : ?>
    Insert content here
<?php endif; ?>

You can add a full width image to the blog index if you choose full width in the container type option.

As Leo pointed out, adding the same content to all single posts can be done with PHP.

If it's an image you're adding to all single pages, you could do this:

<?php if ( is_single() ) { ?>
    <img src="URL TO YOUR IMAGE" alt="" />
<?php } ?>

OK. thanks. I'll try something like that.

So you confirm that I can't have a 100% width header image/featured image within the pages ?

it seems to me i can have a full width image to the blog index

if you choose full width in the container type option.

but i can't do that for the pages, i can't choose a full width container for the heading image, right?

Do you mean for your image on this page?: http://quatrepiliers.com/wordpress/2017/01/stage-tai-chi-qi-gong-paques-2017-inscriptions-avant-le-1er-mars-2017/

no. sorry. i've just found out, as i was not searching anymore. it is possible to have a full width image for the pages with the Page Header (Container type : Full width !!!)
how come i could not find this anymore ?!!!!!
thanks tom, have a nice evening,
v

Glad you found it :)