Exactly, I was going by size of the aircraft.
Unless you know to look for a “hub” on the plane to differentiate them, I doubt you’d know otherwise.
They are basically the same size otherwise, you’d have to certainly agree to that.
A Boeing 747-400 is 231 feet long with a wingspan of 211 feet and a height of 64 feet. The 747 has four engines.
A Boeing 757 is 155 feet long with a wingspan of 124 feet and a height of 44 feet. The 757 has two engines.
I do not see how a person could confuse the two aircraft on the ground.
I can tell the difference between a 757 and 747 when they are flying 30,000 feet over my head.
I, who know nothing about commercial airliners, can always tell a 747 by the bump on the top. No other aircraft have the bump.