I hate shops with photos like this.... However, I have done more than a few. I try to establish camouflage before entering the store: I start the shop with my phone in my hand, texting, emailing, checking out the MysteryShopForum, whatever. I keep the phone in my hand throughout and play with it whenever I am not in the midst of a required interaction. I pace a little. Then when I am facing something that needs to be captured, I snap a picture. So many folks are constantly playing with their phones anyhow, that I fit right in, I've become adept at taking pictures of employees' name tags when needed.
I was on a shop with an MSC owner once and I had to go make a purchase while he stood back and observed. He was not able to see the cashier's name tag and was really frustrated that he did not catch her name. I said that it was a long name of Slavic origin that I could not pronounce. He was astonished when I showed him the picture - including all 12 letters of her name. It also gave him her eye color.
For some shops, it's okay to act like some idiot who can't leave his/her phone alone.
Hard work builds character and homework is good for your soul.