Hi,
I think you are getting confused with several concepts:
-- "is Mine" refers to the application that instanciatated that Prefab, it is true only on that machine, and false everyone else. It has nothing do to with "master" concepts. So User A's Player Prefab will return true if you ask this question on User A's device, and false on User B's device. User's B player Prefab will return true on User B's Device and false on User A's device.
-- "master" within the Cloud system refers the running instance that is acting under the hood as the server, it has nothing to do with the "is mine" concept above. Also, don't rely on this "master" as it can change. If for example the device running currently as the master gets disconnected, another device within that room will be assigned as the master. Again, totally unrelated to "is Mine", and master switch do not affect the "is mine" checks you can run on prefabs.
I am not sure what you are trying to achieve, but I would strongly recommand that you study the Samples provided for Photon networking and PlayMaker:
http://www.hutonggames.com/samples.phpThis demo has all its fsm documented, so you can learn more about the connection processes.
https://hutonggames.fogbugz.com/?W928Using GetOwnerProperties is something to use when your player is already connected and in a room ( it doesn't work if in the lobby). it's also quietly featured in the demo ( in the prefab 'Fsm Photon Player' fsm:'Custom Property'), but undocumented, I don't want to confused beginners here, I am thinking of doing an advanced section for this kind of actions. In there, you'll find the expected processes to access Owner's properties.
Bye,
Jean