Sonic Mania

In Studiopolis Zone there are bug like enemies that, when they approach you, will take a picture of you with a visible flash. Let any "Shutterbug" take pictures 10 times while you are on screen and you will get the achievement. The enemy can be seen in the image below.

The way I did it:
When you are at the last checkpoint and you encounter the boss in Act 1, die. You'll restart at the lamp post and an enemy will appear just underneath the platform. He'll get stuck and take your picture once. When until the achievement pops (I believe 10 times).

This can be attained on the first act of Studiopolis Zone. But before starting, whilst in the Mania Mode screen press Y to bring up the Game Options and enable Debug Mode.

If you haven't unlocked this Zone, to access the Level Select Screen, highlight the save file and hold X followed by holding Start.

When the Zone loads up, transform into a Ring by pressing X and follow the route shown in the video to the area with 2 Shutterbugs. Press A to scroll through the items available until you reach the Starpost. Place it on the level by pressing Y and scroll through again with A until you find the Large Ring and place a few down. Turn back into Sonic by pressing X and collect the Rings and enter the Special Stage via the Starpost. Complete the Special Stage (by hitting a Red Sphere) and return to the level.

To unlock the achievement you need to have your photograph taken 10 times by the Shutterbugs.