In 2020–2021, Huawei transitioned its theme infrastructure from zh.ui.vmall.com to a new domain: theme.huawei.com (also through the app). Reasons include:
Trying to fix my partners Huawei P8 Lite 2015 phone, It says when turning It on "RESCUE MODE Attention! Please update system again... r/techsupport http zh.ui.vmall.com emotiondownload.php mod restore huawei
Based on the text you provided, this appears to be a specific web address (URL) used for restoring or downloading Huawei "Emotion UI" (EMUI) firmware or recovery files. http zh.ui.vmall.com emotiondownload.php mod restore huawei