As with any job application, you will be required to send documents for not only immigration compliance, but also for HR.
Legitimate reasons for requests include:
- Proving compliance with immigration laws regarding who is able to work legally.
- Record who works for the company, so that they can use/implement access control.
- Be able to put someone's name down for tax purposes.
- Setup personalized email/corporate directory information.
There is no website mentioned, so I will assume they use HTTPS for form uploads. Something that isn't mentioned, and can't really be discussed is the backend security.
We are not able to view how the backend database(s) and storage of images are implemented. For all we know, both could be on 1.44MB floppies.
I discussed the privacy aspect in detail with another question of mine, but can't seem to find it. The point being, send low quality (JPEG level 5 or so), black-and-white, one sided images of documents if nothing is specified. This prevents the direct reuse of images as supporting documents in the physical realm.
I will however say it seems quite odd you have a driver's license but not a ID card issued by any state.
Unless there is incorrect understanding, a driver's license is a valid form of state ID. Perhaps I'm incorrect to assume, the driver's license is issued from one of the many states of the US.