Photos on my iPhone 5 (101) but only the latest (23) show up in iCloud My iPhone 5 has 101 photos (&amp; 7 videos) but on my PC > iCloud Photos > My Photo Stream only shows the last 23 of those photos.
Photos in My Photo Stream are saved on the iCloud server for 30 days only.  If many of the photos are over 30 days old then they will no longer be available through PhotoStream:

http://support.apple.com/en-us/HT201317