Specs change all the time - Buyer Beware! Not just Lenovo, all brands. I've been checking on this for almost a year, since I first missed a great sale on a newly issued laptop with fantastic specs. Reviews were all wonderful. I was willing to pay much more than the deal I missed. Then I realized that what I was finding had no Blu-ray as the missed deal did . . . then I scrutinized the specs on what I was finding and they were all over the place even though the computers all had the same name such as "Lenovo Y590". (As I said though, it's NOT just Lenovo.) One of the differences you will be finding IS the SSD size, screen resolution, hard drive capacity.
The first tech mag reviews of the brand new Lenovo Y590 (google for them) say this is a laptop to die for in performance and price, and give all the specs, benchmarks, etc. However, if you look at what is actually on the market, the specs are not what was being reviewed. You can't even find what was being reviewed! All Amazon reviews and elsewhere rarely state the specs they have, they just give a name such as "Lenovo Y580". So far I've found 6 different configurations of "Lenovo Y580".
My suggestions is that you take a screen shot of the specs you think you are getting so that you can compare to what you actually get. I recall years ago reading very fine print on a direct seller's site that said "specs can be changed without notice" - even after you placed the order. I read somewhere else that manufacturers stick in whatever parts they have available or get a good deal on. That's why I haven't yet purchased a new laptop - I'm finding it very difficult to compare prices and specs because they ALL go under the same name but they are different systems.