reinstalling osx on my mid 09 imac.... reboots to mouse and keyboard pictures

I'm installing a new hard drive on imac mid 2009 and it reboots.... I feel great I'm happy it's restarting and then blam the screen flashes wireless mouse and keyboard I would appreciate anybody who is familiar with this situation and why and what are my next steps in this problem with my particular computing device...it would be appreciated and thank you for your attention to this ....