Q&A: Question about Intervals in Chords

Check out Mervyn’s great question about intervals in chords and my response.

Mervyn asked:

I recently discovered your website and YouTube channel and I’m enjoying the content. I have a question about intervals. It appears when musicians talk about them they are referring to the root note of a chord as the starting point to determine the intervals of the notes that follow. For example C E G B C (Major 7th Chord) makes C the root note, E the 3rd, G the 5th, B the 7th, and C the octave. I recently discovered a chord or bass line has intervals that occur as we move from one note to the next which are different from what is heard when the starting point is a root note. By analyzing the Major 7th Chord again and this time doing it note by note to determine the intervals,  C to E is a 3rd, E to G is a minor 3rd, and G to B is a 3rd, and B to C is a minor second. Is it incorrect to think of intervals from this perspective? Do we always have to analyze or label them as they occur from a root note or can we view the intervals as they occur from one note to the next?
You have permission to use my first name if you decide to answer my question in a blog post. Thanks a lot for your time. I appreciate your help.

I answer his question in two ways; keywords: musical understanding of a chord, and fingering.

intervals
I play my Votan XS Marleaux in this video.
Fretwrap by Gruvgear.
I use TC Amplification.
Dean Markley SR 2000 Strings.
WolftrackAudio provided Sound. Many thanks!