There are some restrictions for official AOD skins in Huawei Themes application. You cannot use official logos, you cannot put links here, you cannot use Huawei icons. This kind of skins will never be approved officially, but there is way how to install those custom skins manually. You can find list of custom AOD skins for Huawei smartphones here and below is tutorial how to install it.
1. download any free AOD skin from Themes app (and dont apply), for example this
2. copy your custom AOD skin to internal storage of your Huawei device (if you want to create your own custom AOD skin you need to download and install Huawei Theme Studio
3. in File Manager go to Huawei/Themes/HWAods and copy name of your new downloaded free skin (from step 1, it will be the one with the newest time and date)
4. rename your own AOD skin to exactly same name like the free one and than move it to Huawei/Themes/HWAods, confirm when it ask to replace original file
5. apply skin in Themes application (hit apply button in theme skin from step 1)