Beatty's spokesman told DailyMail.com on Thursday that she had read the entire speech already, and wasn't doing anything out of the ordinary.
"That State of the Union is put out an hour in advance so Democrats and Republicans can read along," the spokesman said.
"And while the speech was going on, she was putting together a statement in response."
The other two congresswomen's offices, however, didn't offer any explanation.
Lawrence's spokeswoman said she was "in an event" and couldn't be reached, and offered no explanation.
It's unclear from the picture what level of Candy Crush she was on. Members of Congress are paid $174,000 per year.
Lawrence has boasted that she is "the only Member of Congress with the experience of a full career in the Postal Service." Her post office career spanned three decades.
Watson Coleman's representative did not respond to a request for comment.
A photographer captured the telling image at 9:42 p.m., according to Getty Images.
At that moment, Trump was declaring that "the era of economic surrender is totally over. From now on, we expect trading relationships to be fair and, very importantly, reciprocal."
Watson Coleman was pictured reading responses to a tweet she sent at 9:30 p.m., at about the time the president drew applause for saying that "in America, we know that faith and family, not government and bureaucracy, are the center of American life".
The Congressional Black Caucus member's tweet left no doubt about her feelings toward Trump.
"I do not share the same heart as @realDonaldTrump and the white nationalists he surrounds himself with," she wrote. "Don't be fooled by the words that were written for him. We know what is really in his heart."
On her screen when the photo was snapped was a disbelieving response from a Trump supporter.
"Of course its about race," Doug Johnson fumed. "Do you ever get tired of screaming about race? Its like crying wolf. At some point nobody believes you."
Tuesday's candid photograph was shot from behind the three women, but a group shot of CBC members posted by Beatty on Twitter makes it clear who they were based on their outfits, jewelry and position.