Kristi would come up with a list of topics and you would have to take a photo that coincides with said topic. I've done several of these types of challenges on Instagram.
Here are some of my photos that I have submitted. I can't remember the topics to each.
I could only assume that the topic on this one was HOT
What I loved most about doing these challenges was that I got to get out and do something that I loved doing. I was always looking for things that would relate to what the topic was and was able to get really creative.
If you have an interest in doing a photo challenge let me know. I would love to linkup.