It’s Google Adsense responsive ad code. The iframes are being generated client side. I imagine it’s possible that the responsive ads are being sized before the template fully loads. But I can’t be the only one who has had this problem with Adsense 
It’s Google Adsense responsive ad code. The iframes are being generated client side. I imagine it’s possible that the responsive ads are being sized before the template fully loads. But I can’t be the only one who has had this problem with Adsense