Image Hover Overlay

To get the a usable image URL for images stored in Drive you need to get the image ID and append to this URL:
Remember that images must be shared publicly.

After getting your code, use the code section of the Embed function to embed it. My code below.

There are several other types of Overlays available such as Fade, Slide, Zoom, Title and Icon.

Image Hover Overlay

Use the title attribute 

<img src="" alt="At Google" title="At Google" style="width:100%">