Photo Challenge

Photo Challenge was a limited-time event that started from 9 July 2015 to 6 August 2015. In this event, players were required to complete certain challenges placed for each cookie in order to finalize 9 photos and receive rewards upon photo and challenge completion. Each "photo" contained between 2-7 cookies with different challenges.

Players could see the photos and their Cookie challenges by tapping the Photo Challenge button at the top middle of the home screen. Each challenge must be completed within one play (not within a combination of several plays) in order to receive the reward, and all cookie challenges in the "photo" must be completed in order to receive 5-10 and another completion bonus. Players could achieve the goal in every episode except Ghost Pirate's Island of Coins and Cookie Relay use was not allowed.

The only Cookies excluded from this event were the L-grade Cookies, Ginger Claus, and Ninetales Cookie.

Unlocking Cookies
This challenge required all cookies except Ninetales Cookie and the special reward Cookies. Some cookies may be really impossible to unlock by the level barrier (such as Gumball Cookie). However with a span of 28 days to complete the goals, it's still possible to reach out most of the cookies without Crystal. See Akrie's blog post for tips unlocking cookies.

Collecting Coins
In general, "Double Coins" from Random Boost could help you much better. Even 10% coin bonus from Burning Time event will count and gave you a considerable help to complete the challenge. You can also do the usual Coin Farming methods, but remember to un-equip your Cookie Relay.

Among them, two are known to be pretty high:
 * 1) Collect 45,000 with Mint Choco Cookie - Use Paprika Punching Bag for "15% Coin Bonus" and treasures with Coin bonus and/or Coin flower producing such as Golden Magic Flower Pot.
 * 2) Collect 40,000 with Cheesecake Cookie - Use Coin Scale or Mr. Fa-Sol-La-Si. You can use either Stuffed Elephant Money Box or Coin flower producing treasures.

Reaching High Scores
Many challenges asked you to reach a certain score. In general, these challenges can be completed with playing in Dragon's Valley or The City of Wizards using "Energy Drains 25% Slower" or "15% Points Bonus" from Random Boost.

Among them the highest score challenges are:
 * 1) 90 million points with Lemon Cookie - Best suitable with any pets generating Blast Jelly (e.g. Foxy Bead, Mr. Fa-Sol-La-Si, Electro Lemon). Since the cookie already gave you the magnetic aura, you can freely use any treasures for slowing energy drain (e.g. Specially made Flaming Cocktail or Supremely Yummy Monster Muffin).
 * 2) 85 million points with Cream Puff Cookie - Best suitable with Mini Jackson No. 2. The cookie also generates temporary magnetic aura during her power, so you can use any treasure slots for slowing energy drain.
 * 3) 80 million points with Blackberry Cookie - Best suitable with Flame Bat (for its combination bonus). The best treasure option is using two Magnetic Energy Recovery Drink and one Mysteriously Magical Star Brooch, but if you don't have them, you can replace with Angel Cookie's Rainbow Feather and Limited Edition Colorful Jelly Crown.
 * 4) 70 million points with Gumball Cookie - Best suitable with Mini Jackson No. 2.

Reaching Stages in Certain Episodes
In general, you will need "Energy Drains 25% Slower" from Random Boost. You are not aiming for scores, so you will focus your treasure slots only for slowing energy drain. However, if you're afraid to fail picking any potion in the stages, you can use Magnetic Energy Recovery Drink.

Among them, some of the farthest or the most difficult challenges are:
 * 1) Reach Stage 10 in Episode 2 with Cocoa Cookie - You can use any potion-producing pets, the most popular ones are Pistachio Firefly or Enchanted Locket.
 * 2) Reach Stage 8 in Episode 3 with Vampire Cookie - You can use Spotlight Fan, Brain Gum, or pets that produces Blast Speed.

Trivia

 * During 31 July 2015, Cookie Run held the record for having the most active events running in one day. There were 7 events running, including this event. Other events that ran were Surprise Squirrel Shop, Alphabet Challenge Event, Win Prizes Everyday!, Target Event (July 2015), We've Reached 50M Users!, and Burning Time.
 * Some pictures from this event were recycled in Cookie Run: OvenBreak for use in the "Play" button's menu in the Flames of Glory update, however they are all cropped in a way that hides certain aspects of the image.
 * Breakout uses the "Seize the Freezer!" image, however due to the cropping of the image, Strawberry Cookie is almost entirely hidden from view besides her foot. Notably, while hard to make out, you can still see the head of the Witch.
 * Trophy Race uses the "Come with me..." image, cropping out all but the rightmost of the Spectral Jellies.
 * Friendly Run uses the "Passionate Runners" image, with Zombie Cookie cropped out entirely and the leftmost part of GingerBrave's candy cane also cropped.