OK. Let me try to explain ...
The HTTP server is needed to deliver the web page that allows (multi)players to access the game itself - just like any C2 game you make, when you export your project to a HTML5 website.
The Photon Cloud server handles the interactions between the players - which of course is something that's not needed when you play a game on a single computer/device. It saves you having to create a game server to do that.
And my PhotonClient behavior saves you having to fiddle with a low level socket plugin to get your players to interact with the game server <img src="smileys/smiley2.gif" border="0" align="middle" />