Why do the avatars of all banks’ WeChat official accounts turn gray?

The image data volume is large and the reception time is long. In order to improve the user experience, WeChat will first display the cached text information to the user, and the image will be gray by default. The avatars of all banks' WeChat official accounts turn gray because the image data is large and takes a long time to receive. WeChat public account is an application account applied by developers or merchants on the WeChat public platform.