Mark Jones, 45, of Cwmbran, denies murdering five-week-old Amelia Jones.
Prosecutor Paul Lewis told Newport Crown Court Mr Jones did not like Amelia's father Ian Skillern and after her birth said she looked like him.
The court heard that Amelia died after suffering a bleed to the brain and a fractured skull.
Mr Jones was looking after Amelia at her home when she was injured in November 2012.
He said he fell with Amelia in his arms on one occasion and passed out while holding her on another.
In summing up, Mr Lewis said: "Mark Jones did not like the fact that Amelia Jones looked like her father."
He described Mr Jones as a liar of "Oscar-winning talent", saying Amelia's injuries were more commonly associated with a "motor vehicle crash or falling down a flight of stairs".
Mr Jones denies murder and the trial continues.
A man accused of murdering his baby granddaughter disliked her because she looked like her father, a court heard.