Look at his post here:

https://twitter.com/SecPompeo/status/1349393269600493571/photo/1

If you assume a raised hand is a [Dash] and a lowered hand is a [Dot], translated in to Morse code it is

-....- (dash dot dot dot dot dash) —.- (dash dash dot dash)

Translates to “-Q”

Look at his post here:

https://twitter.com/SecPompeo/status/1349393269600493571/photo/1

If you assume a raised hand is a [Dash] and a lowered hand is a [Dot], translated in to Morse code it is

• . . . . -
• • . -

Translates to “-Q”