What do the new tray icons mean in wp8.1?

[NokianWP]

For example, I am not familiar with the meaning of the hamburger/tablet with lines icon, or the arrow above the cellular or wifi icons. I can't seem to find the meaning anywhere...

 

[idokamaroq]

I think the hamburger you're referring to means that there is a new notification in the action center and that the arrows indicate that the phone is actively transmitting or receiving data over the cellular or wifi network at that moment