Please try re-installing the launcher a second time and see if it fixes the image.
I'm having the same issue, it happened after the summerset update, I reinstalled the whole game + launcher because of it, cleared all cache, still the same problem.
What it looks like for me:
What it says when I middle click on the ad:
(two ads are like this).
I also tried turning off my firewall and disabling antivirus web protection to see if it helped, it didn't.
If reinstalling the launcher and disabling your anti-virus hasn't helped, you should go ahead and contact customer support to open a ticket. Our support team can investigate into what would cause the launcher images to break.