Q: Just got my iPhone 6s last week and notice theres a small back dot on the uper left of the screen. Is this anything to worry about?  iPhone 6s, iOS 9.0

Hi, Anuja 93.  

Thank you for visiting Apple Support Communities.  

I understand that you have a concern with the display on you iPhone.  Here are the troubleshooting steps that I would recommend going through for this issue.  

If you see lines, missing sections, discoloration, or poor image quality

1. Try to restart your device. If you can't restart, force restart your device.
2. If this doesn't work, restore your device.
3. If you still see the issue after you restore, contact Apple Support.

Get help with the screen on your iPhone, iPad, or iPod touch

Cheers