Why is Lando wearing Han's clothes...
The clip uses incorrect footage, but should have taken the footage from the first film where Han's character is actually featured wearing the vest Lando is later seen wearing at the end of the second film.
My theory is this:
That it is put in the story to remind you that Han is no longer there, & that at that moment, his character is being intentionally sacrificed for the good of the series. The clothes are a well executed plot device complete with subliminal message entered for its residual implication on the audience & its meaning towards the status of the Han character. In a sence Lando has replaced Han & we are supposed to recall Han's sence of significance as something more noble than just the irresponsible/loose cannon hero, it cements his character's sence of importance to the story, since Laya will later on resurrect his character in the next film. The whol wearing of hans clothes pays homage to the loss of Han as a character. This is all funny since he will just be ressurected, but I think it adds to the nostalgia to the film ending on a sad note.