Translation:How many times a day do you look in the mirror?
No, there's a difference between looking at the mirror ("naar de spiegel kijken") and looking in it ("in de spiegel kijken"). With the first one, you look at the object itself (the mirror). The second one, you look at the reflection.
Ii it incorrect to say: 'Hoeveel keer per dag kijk JIJ in de spiegel?'