One way in which Leila could be characterized is being overwhelmed with so much in the moment.  Leila is overcome with the reality of what the moment presents.  The ball, the pomp and celebrated sense of the ornate overwhelms her.  This can be seen in the powder room where the bustle of activity leaves its impression on her.  At the same time, the manner in which the dancing is carried out, along with the decorations of the hall, both cast significant impressions on her.  Leila is far removed from the school in which she learned how to dance and is overcome with the reality of being in such a setting.

At the same time, one can describe Leila as being overwhelmed with the realistic observations of the fat, old man.  The reality of that which awaits her is one that subsumes her.  Leila realizes that there might be some level of truth in what the old man is saying and this becomes painful for her to bear.  At the same time, this condition of being overwhelmed causes Leila to want to flee from the dance and the pain of what she encounters.

Finally, Leila the ending in which Leila wants to be overwhelmed in the moment, dancing with the young man and barely noticing the fat man.  In some respects, Leila is overcome with the moment, dancing as if there is no tomorrow, a vision of the future that has been rendered as a sad one by the old man.  Leila is embracing the condition of being overcome with the moment for it prevents her from having to think and reflect about the realities that were raised in the old man's talk with her.  In this, one can see how the description of "overwhelmed" or "overcome" could help to characterize Leila.