WiFi hotspot without internet provider knowing? I have a MacBook Pro with ethernet internet access on a corporate network. Due to corporate restrictions I cannot wire any other device to the network.

My solution was to create a wifi-hotspot from the mac to share the internet connection with my other devices.

I have some privacy concerns. Due to personal reasons I would not like anyone else knowing that I am accessing internet from a second device (please note that this is not illegal or any violation of corporate policy, it is only a matter of privacy). So I have some questions.

Can the corporate IT admins know that I am accessing at the internet from a different device than the Mac? That is, the HTTP requests that I make from the other device, go through the Mac and then reach the corporate network, are any different than HTTP requests originating from the Mac directly?
Any unencrypted HTTP packets (web sites or even streaming commercial content like music) would by default contain the User Agent corresponding to the device and browser/app, which would make it easy to distinguish between devices. It would be rather involved to change the user agent for non-browser traffic; some of those packets are generated deep within the OS.

Effectively masking a WiFi-connected device would be very difficult, if not practically impossible (depending on the sophistication of IT), if it is iOS or tvOS, or especially if it is a non-Apple device. Different devices and OSes have different characteristics for traffic they create.

You could encrypt the traffic with a VPN on the WiFi-connected device(s), but this could easily be noticed and is likely to be a red flag to IT.

The easiest combination to hide would be a device identical to the wired device, e.g., a macOS laptop over WiFi to a macOS laptop. Even then, source port number patterns and other markers would be a good clue to IT if they are paying attention.

In addition, the mere act of connecting another device is problematic. Operating a WiFi hotspot is likely to be noticed, even (again, depending on IT sophistication) if you hide the SSID. Triangulation could probably isolate the location to within a few machines. You could tether a device using USB, Bluetooth, or another hardware port, but any connected device will also leave forensic clues on the wired device.