Remote disc (another Mac) locked and won't eject

Help! I have an iMac where all my photos are stored and a MacBook Air. To use the photos on the MacBook, I logged into the other machine remotely and accessed them. All seemed fine. But now I have a "remote disc" icon in my laptop finder window which says it is locked and won't eject - and the iPhoto library on my iMac says it is locked and not available to me. I have tried simple things like restarting both machines but it does not help.

What can I do?