..what the heck does that silly archaic phrase mean?

I actually heard it as part of a radio ad today, yes a radio ad. (Font is my editorializing.)

My understanding of radio ads is that they have to be as efficient and concise as possible to get the point across. Attention deficit and all that.

Yes, the parallel I am drawing is that your LinkedIn profile Headline and Summary have to be as terse and tight as a radio ad (at least as much so as most of the others that command my attention). They have to be memorable and draw the reader in. So they will read more about you.

Copy and paste both from your LinkedIn profile page to a Word doc.

Work it and rework it. You may even find a typo or spacing error.And a fresh look may result in an edit, and the final product may just be better and clearer than the original.

Do it. Concise enough?