Green’s Dictionary of Slang

(US black) something excellent; also as adj., fine, good.

1938		D. Burley N.Y. Amsterdam News 19 Mar. 17: The new Mimo club is a blip! a solid blip!
1944		Cab Calloway New Hepsters Dict. in Calloway (1976) 253: blip (n.): something very good. Ex., ‘That’s a blip’; ‘She’s a blip.’.
1960, 1975		Wentworth & Flexner DAS 43/2: blip adj. Excellent; very good. Jive use since c.1935.
1967		P. Thomas Down These Mean Streets (1970) 116–7: She was really a good-looking blip, stone-smooth.
2022		J. Hannaham Didn’t Nobody Give a Shit 158: [She] shoulda worn a banner around her like she in a pageant—Miss Chiff. That'd be a blip.