Annotation text overlay / stream another image ?

[lecho74]

First: With streameye i get the fastest video stream with my rpi zero w - top!

Can i edit the 'html-streaming-page' to display another image
(generated from sensor readings) or from a textfile?
Alternative: Is it possible with an image overlay?

https://picamera.readthedocs.io/en/release-1.13/recipes1.html?highlight=annotation#overlaying-text-on-the-output

Sorry - i am a beginner in this section -