If you are trying to share a PowerPoint presentation using Lync on Mac then you should be aware that this feature is not available yet. For any reason, the feature is not available in the Mac version of Lync and that’s why the option may not be visible. In other words, without this tool you cannot start an online meeting using Lync for Mac, yet. However, it is a good time to send a feedback to the Lync team suggesting this feature in the next version.
So, the feature is not workable for Lync for Mac 2011 and that’s the reason why you may not be able to share powerpoint .PPT on Mac using Lync. Definitely most people can be disappointed and this can be frustrated when you are using it. But your words are valuable for us and we are considering of the customers’ feedback on the using of our software.
You can learn more about the features of Lync on Mac reading this chart.
Another workaround if you need to share a powerpoint presentation on Mac is that a Windows Lync client join to the meeting and they can upload the powerpoint presentation and then the Lync for Mac user can take over the presenting, or you can use an online sharing website such as SlideOnline to share powerpoint presentations.