No. You can't snap a photo of your W-2 or any other form in TurboTax Online, nor can you upload a photo you took with your device's camera.
However, you can take a picture (W-2 only) via the mobile app, which will then upload to TurboTax Online. Please see the following TurboTax FAQ for instructions on how to do so:
https://ttlc.intuit.com/replies/4883700
