It appears that the diode is not in perfect alignment
You are getting a reflection off of the module
The diode may not have been completely pressed into the module or the module may be "imperfect"
In any event, this is not tragic.
It is not harming the laser
It will not hurt its ability to burn
Maybe post a picture of the raw output of the diode without the lens up on a wall and then with the lens on. The raw picture would tell if there is something with the diode and if that is fine then the other would give an idea if it is the lens.:beer:
Ok so it is not the lens. Either there is a real problem with the diodes window. Maybe shake it a little listening if it is loose. Or you have some damage to the lasing cavity on the diode. If it is the window you will need to take extraordinary means as in removing the diode from the module and decanning it and if it is the lasing cavity then may it rest in piece.