The simplest way is to just hold your artwork up to the camera when you'd like to share it.
Some artists also tilt their laptop toward their table or use a second device, like a phone, as an overhead camera. In that case, you can join Zoom from your laptop for your face and join again from your phone placed above your workspace to show your artwork.
If you try this, just mute one device to prevent audio feedback.
All of this is optional. Simple setups work perfectly.