From the attached video (amber_LED), you can see that there is an amber light showing internally from the switch, not from switch external panel.
The other attached video (green_LED) gives you an example of a fast flashing green light showing internally from the switch. They have a different light pattern, but both indicate light from eUSB drive which is normal behavior and has no impact on the operation or status of the switch.
The Brocade team has stated they do not document which products have which eUSB drives so if you notice an LED light showing from the platform of a DS6620B-V2, it should be the eUSB drive. On any other model, confirm with the Brocade Hardware team that this is also an eUSB drive light (open a Brocade ticket and ask TAC to escalate to their HW team).
The Brocade hardware team confirmed that the LED blinking light is from the eUSB card. This LED has no correlation to the health of the switch or its components. Brocade sources multiple vendors for this component and some have an LED light, and some do not. Also, those with an LED light may have different color LEDs to indicate activity. This may be ignored and there is nothing wrong with the switch.