It's simple.  Angela Merkel is touching the outer part of her mask, where virus may have settled.  If so, she has probably transferred it to her fingers.  See how the mask is not tightly affixed around her nose?  Air will travel through points of least resistance, avoiding the HEPA or other filtering materials, to sneak around obstacles.

Of course, Angela may simply be virtue signalling with her mask, not trying to obtain good protection. Or just complying with an emergency law.

The thing is, you can actually increase your risk if you don't use masks correctly. Virus can concentrate on the mask.

  • N95 masks cannot have ear loops, because they don't allow for a tight enough fit.  
  • N95 straps go around your head. 
  • N95s are supposed to have a small electric charge to repel viruses, with layers of polypropylene fibers forming a dense barrier.  
  • They are disposable and intended for one wearing.  
  • They must be discarded after a single exposure to someone who may be infectious.

Achieving this for the population, and even for medical providers, is impossible. Sufficient effective masks have not been produced.  So CDC has been manufacturing mask recommendations out of whole cloth. And CDC just published a study, performed by its own employees, that showed 2 masks work better than one.  Theoretically, of course. Keeping your hands to yourself.  Tying those earloops tight. 

But if one doesn't work, will two work? When is enough, enough?

UPDATE:  The WaPo apparently didn't like me posting Angela Merkel with fingers on mask.  Instead of making the photo disappear, they blurred it. So I selected an AP photo of Angela on a different day.  Meanwhile, CDC keeps trying to turn practically worthless masks into N95s.  The latest attempt:  "reusable mask fitters" such as a piece of a pantyhose leg worn over the masks to affix them tight to your face. No kidding.  Recommended by the new CDC Director.