Even if a design does not depict reality real things have to be referenced to make them have all the nuances and feel of the real thing or else the design will not be convincing.
One of the things we were taught on our university course was to reference everything and to research objects. A thorough example of referencing was the 1960’s illustrator Bill Johnson who would have had to set up a real scene like the one he was trying to depict to use as reference and illustrate in situ from life. Not so easy to running off digital pics as we can now to use at our leisure in the studio. If you take a look at Digger and Harvey with the Strawberry in my design “It wasn’t Me” I have done as I was told with my referencing. Digger is in fact a fox terrier, the strawberry was photographed by me for reference before I ate it up. I know that blackbirds are round as I have drawn them from life, and Harvey well I have drawn him so many times over the years I know him well enough to reference him to himself!