Graphic before title – Specific Category

Try the following code:

function new_title( $title ) {
    if(in_the_loop() && !is_singular('page')) {
        $picArray = array(
            '3' => '⚠',
            '5' => '⛅',
        );
        $cats = get_the_category();
        $cat = $cats[0]->term_id;
        $title = $picArray[$cat] . ' ' . $title;
    }
    return $title;
}
add_filter( 'the_title', 'new_title' );

First, we check if we are in the loop, and our post is not a page. Variable $picArray is an associative array of {category id} => {emoji’s html identity} pairs. Of course, you have to build this array to match your values.