The left hand and the right hand are 'mirror images' (of each other). = The left hand is the/a 'mirror image' of the right hand.
He's the 'mirror image' [=(more commonly) 'spitting image'] of his father. [=he looks just like his father]
She saw her reflection in the 'mirror'. = She looked at herself in the 'mirror'.
(..) Dialogue: Marked=..,Default,NTP,!Effect,-Wanna play chess?\N-No. Dialogue: Marked=..,Default,NTP,!Effect,Harry, l know what you're thinking,\Nbut don't. Dialogue: Marked=..,Default,NTP,!Effect,There's something not right\Nabout that mirror. Dialogue: Marked=..,Default,NTP,!Effect,Back again, Harry? (..)2001 Harry Potter and the Sorcerer's Stone
(..) Dialogue: Marked=..,Default,NTP,!Effect,l look good. Dialogue: Marked=..,Default,NTP,!Effect,Harry, do you think this mirror\Nshows the future? Dialogue: Marked=..,Default,NTP,!Effect,How can it?\NBoth my parents are dead. Dialogue: Marked=..,Default,NTP,!Effect,Do you like yours, Ron? (..)2001 Harry Potter and the Sorcerer's Stone