Yealink SIP-T54S Administrator's Manual page 213

To upload custom wallpaper via web user interface (take SIP-T48G IP phones for
example):
Click on Settings->Preference.
1.
In the Upload Wallpaper(800*480) field, click Browse to locate the wallpaper image
2.
from your local system.
Click Upload to upload the file.
3.
The custom wallpaper appears in the pull-down lists of Wallpaper and Wallpaper with
DSSkey unfold.
To change the wallpaper via web user interface (take SIP-T48G IP phones for example):
Click on Settings->Preference.
1.
Select the desired wallpaper from the pull-down list of Wallpaper.
2.
Configuring Basic Features
187