Mother blasts photo of officer smiling, giving thumbs-up next to her son's dead body 

文章的标题是这样子的，一开始看上去是分词短语做状语以为giving的主语是mother，后来感觉下来并不是 而是officer ，那这句是做定语？那逗号是

谢谢老师回答！

回答如下：

以上句子语法结构分析如下

主语：Mother 

谓语：blasts 

宾语：photo

修饰宾语后置定语：of officer smiling,giving thumbs-up next to her son's dead body

后置定语是一个介词of+动名词的复合结构（即逻辑主语officer+2个动名词短语充当）

上面句子出自于下面文章

Mother blasts photo of officer smiling, giving thumbs-up next to her son’s dead body

The photograph, published last week by a television station, immediately drew a firestorm of criticisms on social media.

“As a momma, this breaks my heart. I cannot imagine seeing this from the people that are PAID to protect and serve,” one Facebook user wrote.

Another called it “sickening,” while others pointed at some racial undertones.

The photo shows a white police officer smiling as he bends over beside a black man’s dead body. Wearing latex gloves, he gives a thumbs-up with his right hand and holds the man’s limp arm in the other.

The name of the officer from the North County Police Cooperative in Missouri has not been released. The deceased man is 28-year-old Omar Rahman, who was found dead last August in a home in St. Louis County. The photo has prompted an internal investigation by police officials and a likely lawsuit from Rahman’s mother, Kimberly Stanton. She found out about the picture after a reporter, who was tipped off about the photo shortly after Rahman’s death, showed it to her.

Related: ‘Brutal’ video shows white officer violently arresting black man sitting on his mother’s porch

Stanton said the officer in the photo, the person holding the camera and anyone else who may have been in that room should be held accountable for their actions.

“I want them punished for what they’d done,” Stanton told The Washington Post. “Because my child, he couldn’t do anything. He was helpless. He was gone.”

Police Chief Timothy Swope told The Post that the officer was positioning Rahman’s body “to do proper crime scene investigation” and to check for any signs of trauma.

“That’s exactly what we were doing,” Swope said. “There’s no malice there.”

He acknowledged that the officer “may have used very poor judgment” for making a thumbs- up, saying the officer “should be more thoughtful of how that represents.”

“We don’t condone that,” Swope said.

He declined to comment about the internal investigation, saying he cannot discuss disciplinary matters.

Stanton’s attorney, Antonio Romanucci, said he plans to file a lawsuit alleging negligent infliction of emotional distress within the next two weeks.

“Clearly, this is a blatant example of disregard for human life,” Romanucci said. “When you take a photograph like that, the expectation is it will be seen by other individuals. They knew this photograph could’ve been seen by his mother. . . . The smile that is on that officer’s face as he’s handling this human body is disturbing. I’m disgusted by it.”