-A font that is even a very subdued color would probably help to make sure the text doesn't get lost when it overlaps with the image.
-Staggering some of the text on opposite sides of your browser images could let you have some control over how the quotes come together on the phone-size screen.
-Probably try out a slightly heavier sans-serif font for the quote, so the text could stand on it's own more where it overlaps with the image.