There may be a Photo App that does that, just have to find it, or wait for one, or write one.
As for the built in MS Photo App.
[DEL]You can create Libraries and add the UNC path, but Windows wants to Index that path on the system you map it to
If the location is huge, then that can kill your performance,(and if it is over WIFI, some routers like to drop connectivity with large amounts of data flow). Netgear and Linksys are notorious for it.
You can try the following trick, but I have not tested it myself.
Windows 7 – Add a non-indexed UNC path as a library | Squid Works
So, in essence, the Skydrive method may be better over all for remote network locations (other PC's, NAS Devices, etc.).
However, I have not tested this either, but I am going to.[/DEL]
This was even easier than I thought,, so I think things have changed in Win8.
On the PC that has the pictures you want to share in libraries,
Go to Pictures under Documents and right click / properties
Add the local path to this so that it will index this on that local PC
Then go to the remote PC that you want to access these pictures on also,
Then do the same, but point to the path.
PC1 = e:\MyPix
On that PC, Right click Pictures under Documents, then click Properties and add that location
This will index it on that system.
PC2 = do the same and add \\pc1\mypix
You will have to create a share to the drive or folder, cause Win8 will no longer allow $ hidden shares.
NOTE: I did this with a folder that has about 15,000 pictures in it. This didn't affect my system at all.