I did it. Is not my “Main Magic Mirror”, I just made it for fun. I have no mirror, only the simple screen. I have used an IKEA RIBBA triple picture frame, this has fit of the width and needs to be shortened only in length. maybe an another tip is to use a strong power supply with 12V 4A and a converter modul from 12v to 5V than use have only one cable 

You are welcome. I guess you will need to find out on your own if the laptop fullfills your requirements. Power consumption is one aspect, another is loudness and heat due to fans in your laptop.

exact like hight of raspi