The reason why the underbelly is obscured is because it was landed undercarriage retracted, and it is a bit busted underneath. Undercarriage down signal was most likely one they were missing from the repertoire they gleaned from signals eavesdropping. Readers with brains larger than a pea will understand why.
Ofir Akunis officially replaces Danny Danon as minister of science, technology, and space (Haaretz)
from the article: Iran says it will not return captured U.S. drone