combining photos

I really like the way the photos were combined at this site. But I don't understand the directions too well in step 3. Could someone please explain this better to me. Are my source and target images supposed to be different in the apply image dialogue box? Because mine end up the same and I can't change them. Any input would be appreciated. Thank you!

http://the-internet-eye.com/TIPS/PSD_collage/PSD_collage_jv.htm

"Are my source and target images supposed to be different in the apply image dialogue box? Because mine end up the same and I can't change them"

Yes..they should be different. The reason you can't change them is because your 2 photos(the ones you want to combine) arent the same size. Open up image> image size dialog and look at the size. Then go to your second photo and look at its size. Then decide which size you like better...and resize the other. Does that make sense??

Like i have 2 images. ones 400x400...the others 400 x 500. Apply image wont work here. I decide i like the 400x400 image...so i resize the 400x500 to 400x400. Now apply image will work.

Hope that helps

That makes perfect sense - thank you! I thought I had the images the same size (well originally I did, then I decided to use a different photo and didn't resize it to the same dimensions as the first photo). I'm going to see if I can get it to work now. I appreciate your help!