def unroll_reflection(thread_count):
    """
    If a threadcount is a symmetrical, as signified by the /, "unroll" it by reversing the
    non-terminal stripes:

    >>> unroll_reflection('B/1 LB1 Y/1')
    'B/1 LB1 Y/1 LB1'

    NOOP if not symmetrical
    >>> unroll_reflection('B1 LB1 Y1')
    'B1 LB1 Y1'
    """
    if '/' in thread_count:
        blocks = thread_count.split(' ')
        return ' '.join(blocks + blocks[-2:0:-1])
    return thread_count