Those shower photos were so posed. He let her convince him to do them just like he let her convince him to do the naked photos on the bed and have sex.
I don't get why so many people are stuck on believing that he would just never do any of that. He ALWAYS did through most of the whole relationship. He knew she was stalking him, slashed his tires, snooped in his phone, email, and who knows what. He knew she was sneaking into his house and hiding in a closet or somewhere to spy on him. He knew all of this but he kept making up with her and having sex with her despite all that.
Just like usual, the day she killed him she weasled her way back into his good graces, they had sex, they took photos of each other naked, she coaxed him into the doing the shower photos, and then she killed him by a surprise attack.
Besides, Det. Flores said there were a number of other photos in the bedroom of them having sex. They've not been made public and probably weren't shown in court because they aren't necessary for trial (the naked ones are sufficient) and probably considered too pornographic. Could be that the prosecution wanted them all in as trial exhibits but the defense was able to keep them out because of their not being necessary to the case and being too pornographic. The naked photos alone were good enough for both sides to agree they had sex before she killed him, so the photos of them having sex just isn't important. And if they had sex and took naked photos of each other, than what is so impossible about his agreeing to have her take shower photos of him if she wanted to?
I think a lot of people here just can't come to grips with fact that despite what he said in that email to her that he once again succombed to her, they made up, had sex, took sex photos of each other, she convinced him to do the shower photos because that was a big part of her plan to get him trapped and vulnerable in order to kill him, and she did just that. Even in that email he wrote her calling her a sociopath, etc., etc., he STILL gave her an out... if she didn't do xyz then he would tell all those people whatever it was he was so angry about.