It is unnecessary and currently broken in that it leads to a repaint. Let's avoid running on this page.
|mediawiki/extensions/MobileFrontend : master||Add lazy loading images test for main page|
Looking at this closely it seems that this bug is invalid. I've written a test that shows that section wrapping and lazy loaded images will not run on the main page.
I think possibly what happened here is an inline image without a height was in the main page causing a repaint. It wasn't related to lazy loaded images.
Thus removing this as a blocker.