Let's say, you have your own room and you want to change some contents in it, like picture on the wall, on tv.., but you don't know how to do that. Don't worry, Photoshop is the most powerful software for that. Read this tutorial, and see how to change a picture on wall and set the picture on tv, on a simple way.
Step 1Open your room picture, or any room picture which have tv, and picture on the wall. You can also use my image below!

Step 2After that, open a picture that you want to set on your tv.
Step 3Take the Move Tool (V), and using drag and drop technique move it on the room picture.
Step 4Take the Free Transform Tool (Ctrl+T), and decrease your picture approximately as your size of tv.
Step 5Then, While your Frre Transform Tool is still active, press Ctrl key, and do like it is shown on the picture below.

After that press Enter on the keyboard.
Step 6
Then, in Pallete Layers for Layer1 choose Linear Light and set Fill to 45%. See the picture below!

Step 7After that, in an equivalent way like we have placed the picture in plasma, put some picture on the wall. See the picture below!
Room before:

Room after:

We're done!
Have a nice day!