Some of the challenges and research activities in Pokémon Go require you to take a snapshot of some of your Pokémon. The trainers who receive them are probably wondering how to proceed, and it is quite simple. These more manageable research tasks were made for those who don't always have the ability to leave the house every day. There aren't many available, but they are becoming more popular and accessible.
First you need to choose which Pokémon you want to take a snapshot. Your choice will vary depending on which Pokémon you need to carry out your research task. You can research your roster to decide which Pokémon you want to choose. When you have made your choice, click on them and you will go to their information page where you can see their stats, how much it costs to upgrade or potentially evolve them. On this page, click on the camera located in the upper right corner of the screen. It is under the star icon.
By clicking on the camera icon, Pokémon Go will ask you if you are in a safe place to enter AR mode. If not, find a location where you can lazily bear to use the app without potentially hitting another individual or where you could put yourself in danger of being hit by others. Click OK when you're good to go.
From there, Pokémon Go gains access to your smartphone's camera and now you need to locate a flat surface. When you find one, you should see bright yellow icons on the flat surface. Click on those to bring up your chosen Pokémon. They should come out of their Pokémon and you can freely click on the icon in the bottom center to photograph them. You can review each photo after completing the session.
During some events, you may even get an image of a Pokémon photo bomb, and when that happens you can catch that Pokémon when you return to the in-game Pokémon app.
The images will go to your camera gallery and you can freely view them as much as you want. You just have to take a single photo of your Pokémon for it to contain for the research activity.