“OMG” / “Give me a second!” / “The phone is full.”
OMG stands for Oh my God and expresses surprise or excitement. It is written in messages and can also be spoken as the letters O-M-G. Give me a second! means “Wait a moment!” The phone is full. refers to its storage. Filling a phone with only forty photos is an exaggeration: Frank is teasing Tina about taking too many.