OK, I think I might have found the answer here: https://wpshout.com/adding-using-custom-image-sizes-wordpress-guide-best-thing-ever/
Thank you Mihaila,
however, the second image I linked is certainly cut. It is a vertical photo, and the text is cut. See here
[caption id="" align="alignnone" width="489"]
cut image[/caption]
this is the original image:
[caption id="" align="alignnone" width="489"]
original image[/caption]
One question: in the loop-index.php (/wp-content/themes/specular/includes/view/blog) in line 135 there is this code to place the image in the “div class=media” section of the post:
<?php if(!is_single() || (is_single() && $cl_redata[‘use_featured_image_as_photo’]) ): ?>
<img src="<?php echo esc_url(codeless_image_by_id(get_post_thumbnail_id(), ‘blog’, ‘url’)) ? />”
<?php endif; ?>
Does that determine which image will be placed there?
Or weather it will insert the original image or the reduced version of the image?