In an outline capital letters can indicate many different things, but almost always they are used to signal a change in topic, or at lease a change in subtopic.
What is the distinction between the text and the illustration that is a result of the difference in medium?
As a teacher, I can see that it is very important to ensure that all of the types of learning styles are made available to my students. I think the biggest distinction between having a visual or illustration and having text is based on what the learner can comprehend and then transfer to use as knowledge on the given subject. A picture not only gives us a visual presentation, but it allows the learner to go further with their own ideas of what they have learned in the past. Giving someone written material allows them to put their own picutures in their own minds; this also is derived from what they have previously been taught.
The theme depicted through Juliet's monologue is B: Love is powerful.
The reason behind this is that Juliet asks Romeo if he loves her and says that if he says "yes" she will believe it but if he swears he does, he may be lying. She asks Romeo that if he really loves her, he must say it truly. This is how she explains that love is powerful.