It's the featured image. If client click on that portfolio, they will see more.
If you want 4 images displayed at the same time at your profile, you need to create 4 portfolios.
So I'm having an issue showing my project file JPG's. They simply dont show up, just the file names. Tried reloading, new browser and nothing works to show these images. I am doing this under my agency profile.
I checked your profile and it doesn't look like you were able to successfully upload the fourth thumbnail on your list of portfolio. Could you try uploading the thumbnail again and let us know if the issue persists.