Change focus on article’s main image

In different templates I create for different sites the main image of an article or a category can be displayed as a banner of a narrow version.

So I have this issue where the main image have a woman for example with a product in her hands that the article talks about.

When the user looks at the blog section where all articles can be browse, the image is displayed completely, but they open the article to read more, the article template is loaded and the main image only shows the neck and the chest of the woman.

it would be ideal to be able to set focus to the main image on each article or category, or any post type, so it can be better used in different situations.