Ask HN: What software is used for those realistic product renderings?
The ones were people make up concept images of what they think the iWatch or iPhone 6 potentially would look like. The more realistic kind.
The product is modeled in 3D and then likely exported to Photoshop where Smart Objects can be used to insert screenshots. You could also insert screenshots directly in 3D using materials.
3D Photo-realistic rendering is quite common these days in the product photography, automotive, and architectural industries.
Often times, a specialty rendering engine is used like V-Ray, Maxwell, or Keyshot.