When a switch receive a frame it will send it to all its port in the same broadcast domain .
Don’t forget that when a switch receive a frame if the port who isnt a TRUNK (Dot1q) there is no tag ( vlan-id )
It assumes that the frame belongs to a VLAN number is was configured to use locally on the receiving interface .
It will floods all ports that belong to the same VLAN number except the receiving port .
