Meteor(React-1.6) -Distorted Graphics

Created a iOS-app using meteor(react-1.6), installed build in iPhone6/iphone6 plus/iPhone7. But the graphics is pretty much distorted. We have tested/developed/inspected the app on browser and the graphics looks sharper, they look good but it is not the case with iphone 6 plus…

What is the reason behind it? Thanks in Advance!