Having been a MSPA certified shopper for many years a shopper must know the "Kenny Rogers" response when you consider taking an assignment. "Know when to do them, Know when leave them, know when to walk away, know when to run!" Paraphrasing Kenny Rogers of course.
Taking pictures is an excuse for using your work product without paying you especially if you are taking pictures of a pizza. The pictures are always fuzzy or at the wrong angle even if they were perfect when you uploaded them. Beauty is in the eye of the beholder that is trying to get something for nothing. You certainly are not going back to to the location to re-shoot the pictures.
I am sure if you did a cart wheel as you left they would know you are the shopper. But there are so many guidelines that would give your head a shake. If "They want what?" flashes through your mind you know people like the Swedish furniture store are trying to get your work product for free.
As an entrepreneur you know what it cost to get your tail into the driver's seat and ultimately into the location. You know how much time it will take. If it is just enough to by Raman Noodles and Mac and Cheese I leave it for the starving Seniors and students.
If it is 20 miles away and I am going there anyway and a quick mailing of a package will get me $10. it is like finding $10 in the street. I will bend over and pick up the $10! I would not go 20 miles away to mail that package if I was NOT passing the door. If I am going to the shore and there is a burger joint or convenience store that will give me lunch and a couple of bucks for gas I got lunch and the MSP contributed to my expense of going to the shore. I would not shop down there if I was not going to the shore. I do not take these ahead of time just in case it rains. It has to be self assigned or I contact the scheduler the day of. The locations can be anywhere along the 20 mile route. If I am passing the door I am going in. I may take several of these shops along the way.
I will most certainly work with a scheduler that contacts me in a panic to tell me the shopper flaked on a shop in a neighborhood that takes a specialized shopper to perform in. I do ask for "combat pay" because there is always a risk even in daylight hours. You may be asked for "change". You may be offered drugs or women you would not touch with a ten foot pole may offer you a personal service. If I am properly dressed and forget to take a shower and use my ghetto ride I look like I belong. The scheduler knows I do not work cheap and I am reliable.
Newbies should have knowledge of the demographic when they accept an assignment. If you do not normally shop there, even if they offer you a ton of money they are offering it to you because not anyone can play the role. This goes for high end shops also. Not everyone can eat a $150 lunch and feel like you belong there. I have, over the years, been invited to lunches and dinners where the menu is read from left to right. If you like what you see on the left it does not matter how much it cost on the right if the price is listed at all.