"inside the pram are pinned abstract black and white sketches, geometric shapes"

It is not true that babies can only see black and white. They can see colours, and their attention will often be held by a brightly coloured object caught in their gaze.

Black and white squares
Public DomainBlack and white squares - Credit: Johannes Rossel, Wikimedia Commons

By two months, their ability to focus has improved, and many do show a preference for black and white patterns at this stage. It is thought that this may be because of the contrast which makes the objects well-defined.