What is the different between these two?

[Greenpots]

I saw these at local store both same label Alcra Pacific Nova 'Hilo Stars' . Flowers are different shape but your inputs.

Thanks
Tony

Ps: 1 of them has black spot on leave

[estación seca]

That's an abbreviation for Aliceara, an intergeneric hybrid between Brassia, Miltonia and Oncidium in the Oncidium alliance.

Sometimes flowers can vary in spotting depending on light or temperature when they were developing.

They are likely tissue culture propagated mericlones. Sometimes mericlones undergo mutation in the cloning process and progeny may be different from the parent.

The only way to tell would be to buy both of them, then grow and bloom them for a few more years to see what happens.

Small black spots like those are common on Oncidiums. They're nothing to worry about.

[PaphMadMan]

The essential difference between the 2 is...

The first flower (picture 2) is the normal appearance of this cultivar, while the second flower (picture 3) is peloric. In the peloric flower the petals have changed to partly mimic the form of the lip.

It is a fairly common developmental mistake in many kinds of orchids, and in Phals and Catts peloric types are deliberately selected and bred because many people find them attractive, or at least interesting. It sometimes just happens as a one-time thing because of something odd in the environment early in bud development, but it is often genetic and stable. Which is the case with this plant remains to be seen the next time it flowers.