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:
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.
Use the title attribute
<img src="https://drive.google.com/uc?export=view&id=1Gkh7acBDY3SFTo5qnMs-sOMCCeowtPAm" alt="At Google" title="At Google" style="width:100%">