That combo appears to be one of two things.
I am guessing that what you are seeing there is actually a
scrollpane being made visible under the combobox. Then when an item
is selected the programmer makes the pane invisible and changes the
font and text of the combo. If you notice the listview pops up but
the v2 control slides the list out slowly. I may be wrong but I
think that you are seeing a little sleight of hand there. Really
really good slieght of hand too!