I buyed new IPhone 6S; It’s giving me a migraine

I'm not sure where you purchased a new iPhone 6S, since those have not been available for a while. Also, I'm not sure what you mean by 'bulb"Bubble" regarding a screen. You will need to try and explain more clearly what you mean. Also, if you are experiencing an issue with the phone and it has been less than 14 days, you should be able to return it for a refund, depending on the return policy of the place where you purchased it.

According to: Adjust the display settings on iPhone - Apple Support

"Reduce motion

If you have sensitivity to motion effects or screen movement on your iPhone, you can stop or reduce the movement of some screen elements, such as:

• Parallax effect of wallpaper, apps, and alerts
• Screen transitions
• Siri animations
• Typing autocompletion
• Animated effects in Messages

1. Go to Settings  > General > Accessibility > Reduce Motion, then turn on Reduce Motion.
2. To prevent iPhone from automatically playing bubble and full-screen effects in Messages, turn off Auto-Play Message Effects.
3. To manually play effects in Messages, tap Replay below the message bubble."