Adobe Tutorial

This tutorial showed me how to place an image within another image. I thought this would be useful for design purposes in any advertisement to create something visually interesting. 

  
Before Images

After Image

The steps for this was to place both images in the same photo so it has two layers. Then resize the beach image so it is covering all of the screen of the TV. Then have the television image selected and with the pen tool trace the lens of it all around the screen until it is closed. Then in the paths right click the shape vector mask and select make selection. Then you will select the beach layer and inverse the selection and delete the outside pixels of the image. Then change the blending mode to overlay, and it places the screen over your beach image. 

Source: 

http://photoshoptutorials.ws/photoshop-tutorials/photo-manipulation/blending-two-images-seamlessly-with-photoshop/Page-3.html