My husband has same iMac, running Yosemite. His has share options in red under Airdrop icon, I must have something set preventing it from showing. How do I find it so I can undo it so it will allow me to share?
iMac (27-inch Mid 2011), OS X Yosemite (10.10.3)
The person you want to use Airdrop with needs to "launch" Airdrop by opening a Finder window and highlighting Airdrop on the left (just as you did on yours).
And, both of you need to have WiFi on.
At that point, the other person's device should be showing in the right column along with yours.
Using AirDrop with OS X Lion, Mountain Lion or Mavericks - Apple Support
OS X Yosemite: Use AirDrop to send files to devices near you
Your screenshots are quite helpful.
Judging from the upper pane, AirDrop is active and checked - but the icon won't turn solid until the Airdrop is happening in real time. Nothing to worry about here.
On the lower pane, there are several possible issues. First, make sure both computers are on the same network. Next, confirm that AirDrop is enabled on both computers - and that both computers are capable of AirDrop; some older machines aren't. Finally, your next step is look at the text that accompanies the attempted link. Are there any messages, possibly in blue, on the bottom of the AirDrop screen? Usually, one of the computers will have a message.
iMac 27 running Yosemite, Airdrop does not show Share options in finder.
