The crossed arms part (only) is the racism allegation signal.
"FIFA has introduced a new official signal to be used when there is a racist incident during a match.
Just like we have hand signals for VAR reviews, penalties, and throw-ins, this new gesture — crossing the hands — indicates a racial abuse alert.
When this sign is made, it tells everyone in the stadium that the match officials have received a report of racial slur or discriminatory behaviour. It also signals that they are taking the matter seriously and are investigating to establish the truth and address the situation properly.
This initiative by FIFA reinforces the message that racism has no place in football"