Great observation. Yes there is what is in my opinion an answer. When God appeared to Abraham in the desert of Mamre.
Gen 18:1 And the LORD appeared unto him in the plains of Mamre: and he sat in the tent door in the heat of the day;
Gen 18:2 And he lift up his eyes and looked, and, lo, three men stood by him: and when he saw them, he ran to meet them from the tent door, and bowed himself toward the ground,
Gen 18:3 And said, My Lord, if now I have found favour in your sight, pass not away, I pray you, from your servant:
Do you notice here that even though there were "three men standing by him" but when Abraham spoke to them he used words like "My Lord" in the singular and not the word Lord's in the plural?
Gen 18:9 And they said unto him, Where is Sarah thy wife? And he said, Behold, in the tent.
Notice how all three men spoke at the same time asking the same question? "And they said unto him" and the word "they" being used in the plural but in verse 10 the word "He" is used in the singular.
Gen 18:10 And he said, I will certainly return unto thee according to the time of life; and, lo, Sarah thy wife shall have a son. And Sarah heard it in the tent door, which was behind him.
And now look at verses 13 and 14 where the word "Lord" is used when God is speaking to Abraham. What happened to the tree men???
Gen 18:13 And the LORD said unto Abraham, Wherefore did Sarah laugh, saying, Shall I of a surety bear a child, which am old?
Gen 18:14 Is any thing too hard for the LORD? At the time appointed I will return unto thee, according to the time of life, and Sarah shall have a son.
We never hear the names of the three men, it is never revealed where they came from and scripture tells us nothing about them yet here they are in a desert talking to Abraham and Abraham is calling three men "Lord" in the singular as if there were just one of them.
These men are God in the form of three men. The Father, The Son and The Holy Spirit. Call me crazy if you want but this is what I get from this whole event.
When God appeared to Moses on the mountain God was in the form of a fiery bush. When Moses was in the Clift of the rock God put His hand in front of the face of Moses so Moses couldn't set his eyes on the full Glory of God but when God took His hand away from the face of Moses God allowed Moses to see God's back side or in a more plan term "His Butt". LOL
God has never allowed any man to look upon His full Glory because yes no mortal man could look upon the full Glory of God and live. But God has appeared to many folks and still does today but never in His full Glory.