The previous design iteration of BFS called for flat tails to connect the tanker and the passenger version and facilitate propellant transfer through acceleration.
But the new version is depicted to have three large, unmovable tailfins, doubling as landing struts, reaching well beyond the fuselage.
How can two such ships dock together?
Are they going to rotate 180 degrees with respect to each other around the longest axis? Or dock by nose? Or will the tanker version have different fuselage? (as it has not go to Mars and land there)