Se "espelho" for texto invertido, use:
SELECT REVERSE('my_text') FROM dual;
EDITAR:
SqlFiddleDemo
SELECT t
,REVERSE(t) AS Mirror1
,TRANSLATE(t, 'abcdefghijklmnopqrstuvwxyz',N'ɐqɔpǝɟbɥıظʞןɯuodbɹsʇnʌʍxʎz') AS Mirror2
,TRANSLATE(REVERSE(t), 'abcdefghijklmnopqrstuvwxyz',N'ɐqɔpǝɟbɥıظʞןɯuodbɹsʇnʌʍxʎz') AS Mirror3
FROM tab;
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