Can I still create stripes in the lawn with a robot lawn mower?

Not for most robot lawn mowers. Stripes are created by the rollers on the back of mowers.  Robot mowers don’t have rollers and don’t cut in parallel lines except mowers which use the GPS RTK system.  These mowers will give the appearance of stripes but it will be short-lived as there is no roller.

Most robot mowers mow in a random pattern i.e. they set off in a straight line and when they turn ( due to the edge of the lawn or an obstacle), they turn in a random direction and set off again.  The Ambrogio range of mowers use technology (mainly GPS) to try and ensure that they don’t cut the same area twice for a number of days to ensure more efficient cutting. Some mowers cut in spirals when they sense particularly long grass.