The thumbnail stored in the map document.
[Visual Basic .NET]
Public ReadOnly Property Thumbnail As stdole.IPictureDisp
[C#]
public stdole.IPictureDisp Thumbnail {get;}
[C++]
HRESULT get_Thumbnail(
Picture** Picture
);
[C++]Parameters
Picture [out, retval]Picture is a parameter of type Picture
Product Availability
Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.
Remarks
You cannot access the Thumbnail though DCOM.