What is the use of CI_database2->load->database when I can reference the database

PHP Code:

/*
db6 = project_orange
db7 = project_banana
*/
$this->db6 = $CI_database2->load->database('project_orange', TRUE);
$this->db7 = $CI_database2->load->database('project_banana', TRUE);

$LoadDatabase = "project_banana";

$this->db6->query('UPDATE '.$LoadDatabase.'.'.$LoadTable.' SET `foo` = "bar";'); 


How is that db6, which references project_orange is able to update a table in project_banana database ?

CI 3.1.2