bug#11070: 24.0.94; Large stippled images not displayed consistently

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: Eli Zaretskii <eliz@gnu.org>,  Ivan Andrus <darthandrus@gmail.com>,
>   11070@debbugs.gnu.org
> Date: Thu, 26 Sep 2019 19:30:32 +0200
> 
> Oh, wow, something indeed did happen.
> 
> If somebody wants to play with this that doesn't have that file
> installed, I've attached it to this message.
> 
> You get the background of the current buffer filled with snowflakes, and
> when you scroll the buffer, things get very messy and ugly indeed

How messy and how ugly?  Can you tell more?  (I have no access to a
system where this feature is supported.)