Anyalyzing a Forbes sentence

The 'however' in the sentence is used to create a distinction between what the author observed in general, found in an earlier sentence. There are some sentences in between, so the connection is easy to lose. When you put them together, the 'however' makes more sense.

"I was expecting a group of Gordon Geckos but instead met a bunch of good natured, fun, regular people – a mix you’d find in any social situation. .... One thing was different however, each had the stoic look of money, not the I’m better than you look, but the comfortable look of a wealth steward."

I'm not sure I understand your follow up question. Absolute modifiers are words that are "absolute" and shouldn't be modified, such as unique and perfect. Perhaps you are asking if it's an absolute phrase? That portion of the sentence is a modifier to describe the "stoic look of money".

KW