Unknown MAC in hotspot with many IPs

I have an odd problem thats somewhat confusing.
One mac addresses connected with different IP addresses issued from the DHCP server.

The MAC address database says its a “Sony Ericsson Mobile Communications” device. So i figured it’s a phone.
But why does it have so many IPs and all of them the same idle time ?
Also those IP address are not on my subnet(s)

please see attached image.
unknownMAC.jpg