Connecting Mac to AppleTV

I am visiting a friend who has AppleTV. I wanted to show some photos.

My friend already had set up the AppleTV. He switched the input on the TV to the AppleTV.

I found a manual for AppleTV at Setup Guide

From my computer, I did the following

• In iTunes, select File -> Home Sharing -> Turn On Home Sharing. The documentation indicated this menu was under Advanced, but it was in File -> Home Sharing.
• Open the same menu and select Choose Photos to Share with AppleTV. It is better to limit the number of photos to share, if you have a lot of photos. It takes a long time for AppleTV to load a lot of photos.
• I had to have my friend authorize AppleTV to use my computer. Only five computers can be authorized.  

Viewing a slideshow.

• From AppleTV, select Computer and then Photos.
• From the settings, select the type of the slideshow. Leaving the mouse over an option will preview the option.
• Move to the top of the slideshow list for some options on music. Select music for the current slideshow or set default music from the library of the computers connected to AppleTV.

On a separate topic, iTunes has another menu for connecting to AppleTV to play music only.

• In iTunes, find the rectangle with the arrow in it. I could not find it where the documentation indicated, but I did locate it next to the progress bar for playing a song. 
• Select AppleTV from the list. 
• When you play music in iTunes, it will play through AppleTV.
• Playing music directly from iTunes will override the soundtrack from a slideshow in AppleTV.