Since Leah (“Leia”, LoL?) and Rachel were indeed, sisters, they were probably similar in height, weight, and general appearance. Consider that Jacob has labored for seven years, and after the wedding feast he’s probably quite ‘buzzed’, and wouldn’t readily detect the switch. Also, as tents were typically fabricated from camel hair, they can be quite dark inside at night. Of course, due to his own anxiousness, like any young groom, “the boy…has no patience.”

Since Leah had six sons and at least one daughter from Jacob, she simply couldn’t have been repulsive. Though, being “so human”, Jacob did favor Rachel (hence the ‘hating’, or more precisely, loving ‘less’), which is why Leah’s womb was ‘opened’, and her sister’s wasn’t, at least at first. It would seem that as Jacob matured, both in life and spiritually, he did indeed love Leah quite intensely. A man deemed worthy to be a Prophet would not mistreat any of his wives, if plural marriage is in effect.