hogs cpu and drains battery on some pages

go to e.g. https://www.lecamp.ch/de/ (only happens with the mobile version of the page since the non-mobile version lacks the image) - the blending of the pictures at the top hogs the cpu and drains the battery at an amazing rate. i see two things here

identifying such pages so we can debug
throttling the cpu for these

Edited Oct 28, 2019 by Guido Gunther

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