A small window opens for a seccond Everytime I start the Macbook, a small window opens for a seccond and disapeared. I managed to take a screenshot for that provided below, 



I have High Sierra OS instilled and the machine config is provided below, 

 

This started from today though this doesnt creates any other issue. However, I'm worried that this may be the symptom of something bigger that would come later point. 

Does anyone see this before or can explain?
I have not seen the OS X doing that ever.

It must be one of your Applications.

The OS X is already fully up and running at the time that Window pops up.