For what it's worth, it's not necessarily customary for sitting presidents to attend funerals of former first ladies. For example, Mr Obama didn't attend the ceremony for Betty Ford in 2011 or Nancy Regan in 2016.
But in true Twitter fashion, people still joked about the President's absence.
A warm exchange between Ms Trump and Mr Obama at the funeral has also gone viral.
The pair appeared to share a friendly moment while seated, which quickly became a meme.
Many contrasted it with the more sombre stills of Ms Trump with her husband.
About 1500 people attended the private service on Saturday at St Martin's Episcopal Church in Houston, where Mrs Bush and her husband, George H.W. Bush, were regular parishioners.
Officials say more than 6200 people came through the church on Friday to pay their final respects to the former first lady, who died on Tuesday at her Houston home. She was 92.
After the service, Barbara Bush was laid to rest in a gated plot at the Bush Library at Texas A&M University, near where the couple's beloved daughter Robin is buried, who died of leukaemia in 1953 at age three.
— With AP