It's a smart remark for when someone does something good, or when one purchased new things for bragging rights. Basically, this phrase is used when one is bragging about something of unimportance. It is used in a sarcastic tone.
"Oh man, my parents bought me a new car!"
"Look at you, moving up in the world."
To succeed at whatever you are trying to succeed at (school, work, tennis, etc.) Usually refering to making more money or doing better. This term derives from the theme song by Jeff Barry and Ja'net Dubois from the show The Jeffersons (1975-1985)
Amber: Hey, Ryan, are you still a brokescrub?
Ryan: Well, I got a job at this ghetto cafe.
Amber: Wow, congrats! Movin on up!