Former Secretary of State swapped out phone picture for a blank silhouette . Said the switch was to raise awareness of gender equality initiative . Came amid huge scrutiny over use of private emails to enact foreign policy . Photograph was seized on to complain about emails withheld from Congress . Rep. Clinton said it 'strains credibility ' to think picture from 2011 does not show Trey Gowdy dealing with Libya situation using private accounts .
Former Secretary of State swapped out phone picture for a blank silhouette . Said the switch was to raise awareness of gender equality initiative . Came amid huge scrutiny over use of private emails to enact foreign policy . Photograph was seized on to complain about emails withheld from Congress . Rep. Trey Gowdy said it 'strains credibility ' to think picture from 2011 does not show Clinton dealing with Libya situation using private accounts .