There was a story on OceanUp about Miley supposedly ignoring some fans on her way into shooting for LOL:
"Miley FINALLY came out of the parking lot, with her back completely turned toward us. She didn't even look or wave at her fans, she just kept driving to the set. I love Miley to death, she is my idol but I can't see why she just cant even wave at her fans. It was really disappointing considering we drove 5 hours just to see her."
The story later updated that Miley came out after she was done shooting to wave to the fans so I guess they got to see her after all.
While it may be disappointing to fans if she doesn't wave or greet them, fans shouldn't really expect anything. Actors are there to do their job and they might not always have the time to worry about pleasing fans who probably aren't even supposed to be around the set.