Stepping back to view your artwork from a distance while painting is important for several reasons.
Viewing your work from a distance allows you to assess the overall composition and arrangement of elements. This helps you ensure that the various components of your painting are balanced and harmonious.
This especially of great importance in te sketching phase. In this phase you can still easily make adjustments. Usually it’s a good idea to give the sketch some rest before starting to paint. With fresh eyes (after a long break or even a night’s sleep) you see the sketch with fresh eyes. Sometimes then you spot some errors.
Proportion and scale
Distance provides a better perspective on how different elements relate to each other in terms of size and proportion. This helps you avoid creating disproportionate or awkward-looking objects.
If you’re too close on your canvas, it’s impossible to have this overview.
Color and Value
Stepping back allows you to better judge the colors and values you’ve used in your painting. When you see the total picture, you can relate light and dark parts to each other. This way you can see if the balance of tonal values is right.
When you’re up close, you might get caught up in small details and lose sight of the bigger picture. Stepping back helps you evaluate whether the details you’re working on contribute positively to the overall impact of the artwork.
Viewing your work from a distance can help you spot flaws that might not be obvious up close, such as unintended patterns, or perspective issues. Or simply forgotten parts.
Taking a step back periodically gives your eyes a chance to rest and provides a fresh perspective. This can help you approach your work with a more critical and objective eye.
Artwork is typically meant to be viewed from a distance, and stepping back allows you to see your work as your audience will see it. This ensures that your painting communicates effectively and makes the desired visual impact.
It also helps to see how much detail is necessary. Not everything has to be overly detailed and smooth (especially not in scenery/background)