Teenager Scarlett Vickers was killed when her father Simon Vickers, 50, plunged a knife 11cm into her chest at their home in Darlington, County Durham, last July.
In the clip, posted the day before she was killed, Scarlett Vickers, 14, can be seen in an all-black outfit, playing with her hair as she holds her phone up in front of her face.
Simon Vickers, 50, denies the murder and manslaughter of Scarlett Vickers, pictured, at their home in Geneva Road, Darlington, County Durham, last July.
Simon Vickers, 50, is accused of murdering Scarlett Vickers, 14, at their home in Darlington, Co Durham, on July 5 last year. The girl bled to death with an 11cm deep chest wound.