"Hey, Mr. P.I. -- sorry, that's doctor P.I. -- you, hold this blue folder and make a serious face while you read aloud to the visiting research associate.
Okay, now, we need this photo to look all sciencey and stuff, so why don't you put some lab equipment on the desk. No, not that lab equipment, the new sparkly lab equipment.
No, don't fill it with that transparent solution you were studying. Too boring. Hey, kid, run down the hall and get me an orange Fanta out of the vending machine. Okay, now SMILE BIG. Not you, professor, just the girls. Say cheese!"