Is it a true three bedroom apartment?

It is.
https://streeteasy.com/guides/renters-guide/renter-types-of-apartments/what-is-a-legal-bedroom-in-nyc-2/

Assuming it has heating.

I think that the OP's point was that there's a photo that appears to show a 3-foot-wide bed, a 2-foot-wide desk, and a less-than-three-foot wide area for passage between the two.

Ali, You may be right but it is too hard to calculate from the pictures. Twin is 38 inch plus one inch on each side will make the bed appx 40inch. 24inch for desk say. So the remaining space will be a little less than 3 foot. So substitute for actually measuring the width.

so=no

From what I can see it is not a true bedroom: it does not have heating (also no AC unit, although it is not a requirement for a room) and it certainly is NOT 8' across. I guess I should be careful paying the money they are asking for a two bedroom place with this maintenance in this building.

But there are three bedrooms, so the minimum dimension is 7 feet, not 8 feet, and each clearly exceeds 80 sq ft total. I assume there is a radiator in that window box (same is true for master and living room)

On heating, even if it does not have a radiator, there are plenty of window units with both heating (Using heat pump with back up heating coil) and cooling. It will certainly sell as a 3 bed room.

Sorry, the picture shows a radiator and a window AC.

I only count 13 windows, not 14... Just sayin'.

Speaking of not bedrooms: How is this even a 1 BR?

https://streeteasy.com/building/224-east-11-street-new_york/16?recommended=1

The space listed as a BR is just under 74 sq. ft (and that with a corner taken out of it, so even less), and 1 dimension is less than 8'.

Grandfathered in under an older code, I suppose.

I have my doubts about it being true 3 bedroom.

If the apartment has three or more bedrooms, one-half of the bedrooms may have a minimum dimension of 7 feet.

The two bedrooms have less than 8', even less than 7' in one dimension ....

.

The 2 small bedrooms are divided from a normal size bedroom

Looks like they did take a two bedroom apartment, split one bedroom into two and are now selling it as if it were three bedroom (certainly asking for it as if it were 3 or even 4 bedroom apartment).