Work environments can be as diverse as the people working in them. Often times, employees wish to decorate their workstations with personal items to make their spaces feel comfortable while they perform their tasks. What sort of policies can your company put in effect to regulate appropriate workplace displays?
Typically, employers decide what amount and type of personal items are appropriate based on the culture of the organization. In workplaces that need to maintain a formal and professional image – perhaps because it has frequent visitors – the employer may want individual workspaces to look neat and tidy. In casual settings these restrictions likely don’t apply, and employees enjoy more freedom in how they make their workspace their home away from home. It really comes down to what you’re comfortable allowing.
In most cases personal items don’t cause any issues, and I recommend against having a specific policy on the matter. Should any issues arise, carefully review the problem and adjust or create a new policy based on your findings. Flexibility is often best as it allows employees to be creative and make their workspace their own. When there are things in the workplace to psychologically interact with (like plants, personal photos, and art), employees tend to be more productive and engaged.
It goes without saying you’d want to prohibit anything that is harassing, offensive, or causes a workplace distraction. These prohibitions, however, should already be covered in your code of conduct and harassment policies.