Moses said, “Now show me your glory.”

What was his mood/tone when he said that?

Let's see the context.

Exodus 33:

15 Then Moses said to him, “If your Presence does not go with us, do not send us up from here. 16 How will anyone know that you are pleased with me and with your people unless you go with us? What else will distinguish me and your people from all the other people on the face of the earth?”
17 And the Lord said to Moses, “I will do the very thing you have asked, because I am pleased with you and I know you by name.”

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At this point, the Lord was very agreeable and pleased with Moses. They were like friends. Then Moses made the amazing request:

18 Then Moses said, “Now show me your glory.”

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There was no hesitance, immediately

19 the Lord said, “I will cause all my goodness to pass in front of you, and I will proclaim my name, the Lord, in your presence. I will have mercy on whom I will have mercy, and I will have compassion on whom I will have compassion.

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The Lord didn't rebuke Moses for making the request. Instead, he agreed to do it.

Was Moses impertinent by requesting that the Lord display his physical to him?

No. The Lord treated Moses like a friend.

Exodus 33:11a

The LORD would speak to Moses face to face, as one speaks to a friend.

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