Exod. 16:10 proclaims that Jehovah's glory "appeared" in the cloud--it was some kind of visible manifestation. Compare Exod. 13:21; 16:7; 24:16; 40:34-35; Numbers 16:42; Ezekiel 3:23. Ezekiel 43:2 states that the earth shone because of God's glory.
It's hard for me to understand how one can deny that YHWH's glory in Ezekiel 1:28 is visible, bright, and overwhelming to the prophet. I also do not necessarily see the brilliance restricted to lightning in the verse: "The meaning is, In the brightness, or light, that was about what I saw, was the appearance of the rainbow" (Benson Commentary).
2 Cor. 3:18 mentions beholding the Lord's glory-DOXA "as in a glass" (KJV) which again connotes visibility on some level. Furthermore, Paul urges that "we" are changed "into the same image from glory to glory" by the spirit of God.
This page contains plenty of information on DOXA: https://www.studylight.org/lexicons/greek/gwview.cgi?n=1391
The rendering "glory" is vague, but the basic idea is still conveyed that the word DOXA potentially refers to external splendor, an outward manifestation of brilliance, etc.