Fact check here. I get this ad on social media that claims broccoli makes a small 'nino' head that must be harvested before rhe rest of the plant will mature. And they want us to buy thr nino heads so they don't get wasted. Sounds like total bs to me. Sounds opposite of my understanding, which is the main head is the biggest and smaller side heads may form later. Am I right?

All in the variety. Maincrop varieties grown by most commercial and market growers form a large central head for once over harvest. Green Magic, Castle Dome, Lieutenant are examples. Aspabroc, Artwork are popular among niche grows and casual gardeners. This type may make a small head, but is noted for a multitude of florettes.

Thanks, Dillard.
I still suspect that ad I am seeing is not exactly honest, it's one of those ' food rescue' subscription services.

Concur; Deception seems to be an integral component of advertising. However broccoli is a very versatile plant. It can give a big beautiful head only. Very useful for large scale harvesting. It can give you nice head and subsequent side shoots, useful for home gardeners. It can give you a medium head accompanied by multiple shoots, just gaining favor among consumers. Lastly there is the ancient sprouting broccoli, which consist entirely of shoots. Broccoli (Brassica oleracea 'Purple Sprouting')

I have never previously heard of a "food rescue subscription service"

You know, those, 'Less than perfect' ones? I don't know what else to call it and won't dignify this one with a link, even if I remembered the name.

Imperfect Foods, Misfit Markets... are a couple.

It does seem like a good idea... and yet - they apparently haven't "hit" the UP yet? LOL