Second RPi A connecting to WLAN record

Now I am trying to connect a second RPi Model A to the WLAN.  I thought this new RPiA2 would be assigned another IP address different from 192.168.1.40.  But surprisingly it is assigned two addressed, one is ...40, another new one  ...46!

I used PuTTY to first log in as 102.168.1.40 and it was OK.  Then I logged in as 192.168.1.46 and also OK.  I was confused of what is going on.  Perhaps I should connect 2 RPiA at the same time.

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