I discovered this today by randomly scrolling on my startscreen. I know I might seem crazy :grin: but since I found this it's been bothering me a lot (just because I know it's there, not visually bothering). Just look at the guidelines in the attached picture; you can clearly see that the Twitter and Cortana tiles are 2px taller and 2px wider than the other tiles. I'm not sure if it's just my phone or if it's every other phone but anyway, here is the picture: