Why would this book be for you? Do family relationships interest you? Are you more interested the more complicated those relationships become? Do you like history between your characters and diving into the lives of the secondary characters? Do you like drama, and OTT drah-mah? Do you find emotional conflict engrossing and want to cry, laugh, swoon and be angry at the one book? Do you love sweet high school romance that at an instant can turn dark? Are you ready to get drunk at a party with your favourite character and then begin to question what you love about them? Do you want to go into the book siding with one twin and then keep flip-flopping throughout the read about which twin you relate more heavily too? Are you ready to question every fibre of your being as to whether it's ok to like certain characters and wonder who exactly is lying to you, spreading rumours, and keeping secrets?
If any of that floats your boat, give In A Mirror a read. :)
So obviously I find this book a 5 star... I wrote it.