Sharing content with a colleague is done through Collaboration. 

You and your collaborator can work together on a CustomShow and see the changes made by the other user on the real time basis. 

You can even leave comments for your collaborator for co-ordination. 

This allows you to work on a presentation together which will complete your presentation faster and in sync. 

You can be up to date on what all changes your collaborator made in the presentation in no time. 

Please check the steps below to add collaborator in the link.