I asked around, but couldn't seem to get a straight answer as to what this phenomena was (I must have asked the wrong people).
Turns out, they were textures. If you haven't used them or never heard of them, you need to try them! Textures are images that you lay on top of your photographic image, using layers (as in Photoshop, Corel Paint Shop Pro Photo, etc.).
Using layers in your photographic software, you have the ability to adjust a plethora of variables in both your photograph and the texture of your choice to make the final product look the way you envision. For example, you can make the texture layer on your photo lighter or darker, parts of it lighter or darker, softer, change the hue, change the levels, add text - anything you want!
Here is an example of an image using a texture with text:
|Dream Flowers, Kara Stewart, Art in Photography|
For this one, I took my shot of a tobacco barn, then played with it using another one of Kim Klassen's wonderful textures. And then gave it a border and text and turned it into a poster for my shop on Zazzle.
Click here for how I did it and comparison shots without the texture.
I really liked the historic document feel Kim Klassen's pourvous texture gives this photo I took on a trip to Jamestown, Virginia. The aged parchment feeling seems to set off the replicas of English drinking vessels and ship's navigational tools from the 1700's.
I have not been using textures very long (a year or so), and still have a long way to go to be proficient with them. For some reason, my images with textures tend not to be as light, ethereal or 'feminine' as some of the wonderful images you can find at Kim Klassen's Texture Tuesday. Please do browse there to get a feel for the wide variety of things you can do with textures.
And then play and have fun!