I'm not very familiar with the idea of theophany, but using the definition given by Wikipedia, this is obviously one.
[Theophany] refers to the appearance of a deity to a human or other being, or to a divine disclosure.
Warning: The rest is speculation.
Looking at just this passage, Jesus didn't need to have a human body. God did appear in non-human form to Moses, too:
Exodus 33:17-23 (ESV)
17 And the LORD said to Moses, "This very thing that you have spoken I will do, for you have found favor in my sight, and I know you by name." 18 Moses said, "Please show me your glory." 19 And he said, "I will make all my goodness pass before you and will proclaim before you my name 'The LORD.' And I will be gracious to whom I will be gracious, and will show mercy on whom I will show mercy. 20 But," he said, "you cannot see my face, for man shall not see me and live." 21 And the LORD said, "Behold, there is a place by me where you shall stand on the rock, 22 and while my glory passes by I will put you in a cleft of the rock, and I will cover you with my hand until I have passed by. 23 Then I will take away my hand, and you shall see my back, but my face shall not be seen."
Why would anyone die if they saw the Lord's face? This isn't a permanent condition:
1 Corinthians 13:12 (ESV)
12 For now we see in a mirror dimly, but then face to face. Now I know in part; then I shall know fully, even as I have been fully known.
Revelation 22:3-4 (ESV)
3 No longer will there be anything accursed, but the throne of God and of the Lamb will be in it, and his servants will worship him. 4 They will see his face, and his name will be on their foreheads.
The reason a human being can't see God's face is their own sin. In the Paradise, Adam and Eve were originally not sinful, and so they could see God face to face. After eating the forbidden fruit, they had only yet chosen sin, but weren't yet full of sin. They did go into hiding of their own accord, but seeing God was not yet deathly at that point, and so God didn't need a human form to appear to them.