The computer has sent the image through outlook. (pops out then back in for new text) The wifi has been connected to the computer or laptop and split into smaller pieces to get to your friend quicker. (pop out pop in) The Ethernet cable connects the device to wifi and then to the internet.
The internet is given to us by a company called an ISP.(pop in pop out) An ISP is an Internet service provider like telstra or optus.
Once it reaches its destination it reforms to its original state. (pop in pop out) Cloud Storage is the area where the email was opened, In Outlook.
The hard drive storage is in the phone itself and where your friend downloaded the image to. (pop in pop out) The image is then saved to the photos app and set as the backgroung