Similar to "A tall glass of water" (tall woman with long legs and beautiful features.)

"A tall glass of milk" is used to describe more particuarly a tall white woman (or a fair woman of European decent) with long sculpted legs and a brick house body.

This term is used usually by (older, pimp-ish) black men - hence why the glass is filled with milk rather than water. (Water could mean any race/color.)
"Now that's a mighty fine tall glass o' milk right there!"

"Whew! I need me a tall glass of milk like that there Klohe Kardashian."

"Ooooweee!! That tall glass of milk would do this body good!!!"
by MizzieG June 5, 2013
Get the Tall glass of milk mug.