Wearing a hijab doesn't cause anything. People having prejudice is the cause. The hijab just allows this white girl to experience it.
People CAN choose their religion, but should they based off of how other people make them feel about it?
You're missing a step... "Your religion makes you feel bad" NO! Other people make me feel bad about my religion. That's pretty obviously prejudice.
Also for most groups of people they don't chose their religion and can't simply change it (family pressures), and while what is described in the article refers to religion (hijab) having dark skin and speaking farsi or urdu is just as likely to cause the reaction in people due to fear of muslims, the prejudiced people are just as likely to filter on ethnic/nationality grounds as religious ones.