White House Press Secretary Karine Jean-Pierre says COVID-19 testing protocols remain in place for anyone meeting with the president. Her comments come after members of the Israeli delegation tested positive. Asked if Israeli President Herzog was tested, Jean-Pierre says, "anybody who meets with the president does indeed get tested."
"COVID mitigations for me, endless infections for thee" 
I've still yet to find a satisfying explanation on the data and how it's collected for that graph.
While that totally may be the case, because it is measuring the Labor Force, the dip may be from the mass lay offs when we went into lockdown. That dip does coincide with the brief time period where we 'flattened the curve' and libs gave a shit. But again, lack of a good run down of the data makes it difficult to tell.