Specifies the URL of the image that is used to represent your Office Add-in in the insertion UX and Office Store.
Add-in type: Content, Task pane, Mail
<IconUrl DefaultValue="string" />
|DefaultValue||string||required||Specifies the default value for this setting, expressed for the locale specified in the DefaultLocale element.|
For a mail add-in, the icon is displayed in the File > Manage add-ins UI (Outlook) or Settings > Manage add-ins UI (Outlook Web App). For a content or task pane add-in, the icon is displayed in the Insert > Add-ins UI. For all add-in types, the icon is also used on the Office Store site, if you publish your add-in to the Office Store.
The image must be in one of the following file formats: GIF, JPG, PNG, EXIF, BMP or TIFF. For content and task pane apps, the image specified must be 32 x 32 pixels. For mail apps, the image must be 64 x 64 pixels. You should also specify an icon for use with Office host applications running on high DPI screens using the HighResolutionIconUrl element. For more information, see the section Create a consistent visual identity for your app in Create effective Office Store apps and add-ins.