Custom Post type showing up in loop, regular posts are not showing up

At first, not everyone knows, but definetly should know, that there is a pre_get_posts hook which should, in most cases, be used instead of query_posts.

Further, defining only one custom post type results in bringing just one custom post type. It’s correct. When one want to bring both, custom post type and posts, one should use the abbility of post_type param acceptiong array, not only string. Thus, try this code:

function show_mini_feeds_on_home( $query ) {
    if ( $query->is_home() && $query->is_main_query() ) {
        $query->set( 'post_type', array('post', 'mini-feed') );
    }
}
add_action( 'pre_get_posts', 'show_mini_feeds_on_home' );