Joseph bows respectfully before his father and then brings his sons towards Israel to have him bless them. He even arranges them so that the eldest son, Manasseh, will be positioned correctly to receive a firstborn's blessing. [Actually, Joseph or one of his 11 brothers will be receiving this passing on of the firstborn's blessing soon when Israel gathers his sons to give them his final words. However, it seems that Joseph expected some greater honor or blessing for Manasseh as the firstborn of his sons, so he carefully positions him so that there will be no confusion on the part of his aged and nearly blind father (v.10). I wonder if somewhere in Joseph's mind he was also thinking back upon events in his own family's history, when his father deceitfully stole his twin brother Esau's blessing from his father Isaac? There would be no mistakes this time.
However, the purposes of God are always accomplished in the end, despite our careful attempts at controlling our circumstances. For Jacob has a different goal in mind:
"But Israel reached out his right hand and put it on Ephraim's head, though he was the younger, and crossing his arms, he put his left hand on Manasseh's head, even though Manasseh was the firstborn." (Genesis 48:14 NIV)
Things are starting to get interesting here. Why is Jacob doing this? Knowing the years of turmoil which his own manipulations of his father's blessing brought upon himself and his family [for after Jacob fled to his uncle Laban's home from his brother Esau's wrath, he never saw his mother again, and was not reconciled with his brother until years afterwards, and that rather incompletely], why would Jacob 'mess' with the proper order of such blessings?!