Why is she looking at her hands in the end in movie Morgan?

The original script is a little more telling. It would appear that in much the same way that different divisions of Omni Consumer Products developed multiple robotics programs, Omnicron Corporation has allowed multiple divisions of the company (including SynSect) to develop their own genetic assassins, with some projects dramatically more advanced than others.

The staff are somewhat suprised to learn of a second facility;

LEE (CONT'D): Clean up crew from corporate will be here at daybreak to collect the specimen and transport it for a full autopsy at an alternate facility.

ZIEGLER: Alternate facility? Absurd. Absolutely absurd. Even if - if - I were to consent to the manual termination, there's no one else able to process the minutiae of the work involved. The work must be done here.

and we receive proof positive of a second program

JIM BRYCE (V.O.): But I think these events make it punishingly clear what I had already suggested....

INT. CORPORATE TRUCK - DAY Morgan's corpse is settled into its casing, the lid closed.

JIM BRYCE (V.O.): The L9 [Lee] was the inferior program.

A common feature (and presumably one that "Corporate" has insisted on) is that the hybrids are mentally conditioned to periodically perform a particular gesture, thus allowing those in the know to tell the difference between a human and a hybrid.

The hand gesture is the film's way of offering a twist. In the final scene we realise that Lee isn't just another "suit from corporate". She is, in fact, the product of their secondary lab, sent to Synsect's 'Grant Farms' laboratory with the explicit instructions to not only assess the risk that Morgan poses but also to terminate her should the scientists prove unwilling or incapable.