Well does your phone work? Since you are in taiwan I am surprised if it does. Droid is not a GSM phone so might have something to do with roaming and not being able to find a CDMA signal.
If all you want is WiFi, turn Airplane Mode on, then turn WiFI on. That triangle is alerting you that there is no data service. The reason it is showing is something on your phone is trying to use data, but cannot find a signal. Turning on Airplane Mode will save you battery as well as get rid of the notification
Well, it's a notification like any other, and when you tap it, it explains what it is. Nothing more to it, although it does cut itself off, "You have lost data connectivity," sums up exactly what it means.
So, it is documented, that icon is for Notifications.
We're running in circles because we're over interpreting what the OP wants.
The black icon is a warning notification that something isnt the way it's supposed to be (USB Debug on, bad data signal). If you want to fix it, I offered a solution, if you dont care and just want to know what the icon is, then we're pretty much done.