After a few weeks of tortured crossover themes, we are back in the land of no-brainers with that image, taken about two weeks ago at the Anime Expo. This one, frankly, should 'Shop itself.
You need instructions? That's already funny. Add more funny. As the image already is video-game themed, you may do as you please and still be on topic.
Source Image: Portal 2 cosplayers at Anime Expo, by @meteor_
Note: That image is 1600 by 1200 pixels. I included the largest size to aid you, but if you use it as your base image you will likely have to resize it to 800x600. Just make sure it's over 640px wide, I need that width to do the "Winner" image, if you want me to pick yours.
With that caution out of the way, let us now bring in the monks to read the tome of how to participate in the Kotaku 'Shop Contest, post Kotaku redesign.
[gregorian chanting]
1. Create your 'Shop.
2. Upload it to a free image hosting service. I suggest imgur. It's stupid simple. No account is necessary.
3. This is very important: You must use the URL of the image itself. In imgur, this is the second URL it gives you after you upload the image. It's under "Direct Link (email & IM)"
4. At the beginning of the comments roll, click "Start a New Thread"
5. To the right of your name, select "Image."
6. Paste the imgur URL in the image URL field. It's the field that says "Image URL."
7. You can add editorial commentary if you want, but then just hit submit and your image will load. If it doesn't, paste the image URL as a comment.
8. This is important: Keep your image size under 1 MB. It will not upload to comments if it is over that size. What's more, we're getting reports that if your 'Shop is more than 1000px tall (vertical), it won't upload. If you're getting the broken-image icon, try resizing to a smaller dimension.
As an added inducement, I want to let you know I do star commenters who send in worthy/funny submissions - whether or not they're chosen for the final 20. This may not happen immediately. I usually start rounding up a gallery by the middle of the week. This is my subjective call, but I do want to recognize as many contributors as possible, and show gratitude for making this such a popular feature on weekends.
Now, Gentlemen, start your 'shopping!