There's no such thing as photon matter. What was made were some interesting states of regular matter interacting with photons. The substrate remains regular matter. It will look like regular matter (in this case, being a gas, probably not very interesting) and it will interact like matter.
The theoretical properties might be very interesting and varied, but they almost certainly won't involve the creation of exotic matter with strange and exciting interactions with regular matter.
For other vaguely related things, read up on surface plasmons and polaritons, which also involve coupling light with regular matter and some interesting effects coming out but without somehow creating a new kind of matter.