Publisher allows you to videos in the page, just like embedding a website. This allows users to view the video without leaving their homepage. To do this:
First, you need to go to the page Designer
On the left side, you will see the Embedded Site module listed in the Modules section
Click and drag the module onto the page. A window will popup. Here, you can paste the address of the video you wish to embed in this box. This will validate that it is a website address (e.g. https://www.yoursiteurl.com)
The security of the url must match the security of your portal. If your portal is SSL enabled, your site must be HTTPS. If your site is not SSL enabled, your site must be HTTP. This is a requirement of modern web browsers.
For SSL portals, YouTube videos must also use "Privacy Enhanced mode". To do this, go to the video's page. Click Share, then Embed, then Show More. Check the box for Enable privacy-enhanced mode. Then, copy the video address from the embed code like you see below:
And paste it into the popup window
Once you have the address, you can modify any style properties by clicking "Choosestyle". Here, you can set borders, background colors, etc
When done, drag the handles around the dashed box to re-size your embedded video to your desired size.
When done, click Save. The embedded site will reload every time the homepage refreshes