Cell is not an object-relational mapper. It is a programming language that uses relations to encode data, instead of records and pointers. There's a world of difference between the two. ORM helps you load/store your data from/to an SQL database, but once your data is in memory, all computation is done using objects. In Cell, on the other hand, computation is done with relations.
In that example, ORM is never mentioned: it's just a comparison between two different programming paradigms, functional/relational programming and OOP. It's not unlike comparing, for example, ML-style functional programming and OOP.
A comparison of the reactive part of the language with a framework like, say, ReactiveX would be interesting, and will be added at some point, once that part of the language has matured.