Capt. Jonathan Crisp also told jurors that England, charged with seven counts of conspiracy and abuse, had learning disabilities and was prone to clinical depression that made it difficult for her to function as a soldier in the constant stress of the Iraq prison.
Crisp said England posed for the photos to please Pvt. Charles Graner, the former Pennsylvania prison guard described by prosecutors as the abuse ringleader, and that she didn't think she was doing anything improper.
"The only place she felt safe was with him. She was happiest with him," Crisp said during his opening statement. "She was able to block out the surrealness of the environment she was in."
England placed her faith in Graner's actions because he outranked her, was much older and an experienced guard, the lawyer said.
Graner, who England has said fathered her young son while they were deployed, is scheduled to testify as a defense witness. He was convicted in January and sentenced to 10 years in prison.
Prosecutors countered that England's smiles and thumbs-up in the photos taken by Abu Ghraib guards in 2003 show that she was a willing, even eager, participant in the abuse.
"Pfc. England was very actively involved in what was going on," Capt. Chuck Neill said.
England, 22, is charged with two counts of conspiracy, four counts of maltreating detainees and one count of committing an indecent act. The reservist from West Virginia faces up to 11 years in a military prison if convicted.
England's defense team took a different approach than her co-defendants by opting for an all-officer jury, which was selected earlier Wednesday. Two Abu Ghraib guards from the Maryland-based 372nd Military Police Company were convicted by juries made up of officers and enlisted personnel, and six soldiers made plea deals.