This picture, and the ones that will follow, are the results of several things:
1) I believe you can have a picture be suggestive and erotic without being explicit.
2) I have been doing too many pictures "for" something (for roleplaying games, for a model's vision, for learning a new technique, etc.) and I decided to do some pictures just "for" the fun of it.
3) I've recently purchased a book on Erotic Manga and the "idea" of each of my pictures comes from one in that book...although the result is totally different.
So to get back to your question, she is an innocent and afraid that she will soon have too little clothes on while someone sits in that chair and watches.