iOS8.3 bug after unlock screen

After update to iOS8.3 on my iPhone 5C I have notice interesting bug. When I unlock screen I can see that upper status is bigger than usually for 1 seconds. After this short time size of status bar goes back to normal size. It is not big problem. But I did not have this bug on any previous version iOS. Do anybody have this bug?

Here are photos for better understanding:

Bigger status bar immediatlely after unlock:

Normal size of status bar after one second: