Sorry to hear that you find the caption confusing.
Basically, each image shows a photo of some flowers with a Pattern Fill layer over it. The three different versions show the result of using different blend modes to combine the photo and the Pattern Fill layer:
-The top image has the Normal blend mode applied to it.
-The bottom-left image has the Linear Dodge blend mode applied to it.
-The bottom-right image has the Hard Mix blend mode applied to it.
There's an error in the final sentence of the caption that's probably adding to your confusion: Instead of "Dissolve," it should say "Linear Dodge."
I hope that helps.
Associate Editor, Missing Manuals