In this case, SPACE() function would add white spaces depending upon the condition given in WHERE clause. The following example from student table will demonstrate it.
Example
mysql> Select Id,Name,Space(5) from student WHERE Name='Harshit'; +------+---------+----------+ | Id | Name | Space(5) | +------+---------+----------+ | 15 | Harshit | | +------+---------+----------+ 1 row in set (0.00 sec)