My app icon doesn't shown on admob

I have published my app through Google-play and when searching it in AdMob in order to link it, I found it but without an icon, the name of the app is correct and my name is correct(developer name) but it has no icon despite the other apps have:

I don't know if that related to AdMob only or it will be like that in some other devices, and I don't even know why it is like that on AdMob and if that OK or not. worth to mention that the icon displayed normally when tried to access the app through the app store from the PC.