To see this, look at https://test.wikipedia.org/wiki/Mapframe#GeoShapes_external_data - Note how the Interstate Highway I-696 example does not specify a zoom/lat/lon, and autopositioning is not working in snapshot service. The Alaska example looks good because zoom/lat/lon are specified.
for example:
<mapframe lat=. lon=. zoom=.> { .ExternalData - WDQS query. } </mapframe>
if the lat/lon is missing, the map breaks.