If you go read Lily's blog, you can find out more about her border crossing. The picture is something she mentions in her own blog. And while it's certainly not against the law to have such a picture on one's camera, when taken in context with the rest of Ms. Sussman's accessories and commentary, raises suspicion in the eyes of a wary border guard.
Police officer killed, 13 people wounded in car bomb in Turkey's Gaziantep, official says (Reuters)
from the article: Police shoot U.S. student's laptop upon entry to Israel