Selena Gomez's evolution from Disney performer into a mature pop star owes as much to her ambitious use of visuals as it does her increasingly daring themes and sounds. Her slinky performance on “Good For You” is punctuated by stark shots of her wallowing at home, and she takes on multiple roles on the playful, ‘70s-set “Bad Liar,” hamming it up as a shy student, a flirty, mustachioed teacher, and a perky sports coach.