It's challenging to interpret specific actions or behaviors without knowing the broader context and the individuals involved. People have different ways of expressing themselves, and subtle gestures can have various meanings depending on the situation, cultural background, and personal preferences.
In some cases, brushing someone's upper back with a shoulder could be a casual and unintentional physical contact, which may not hold any significant meaning. People often interact physically without attaching any romantic or emotional connotations to it.
However, if this action is intentional and seems flirtatious or intimate, it could be a subtle way of showing interest or attraction. Physical contact can be a way for some people to communicate affection or create a closer connection with someone they are interested in.
The best way to understand the intention behind this gesture is to consider the overall context of the interaction and the relationship dynamics between the two individuals. Pay attention to other cues, such as body language, eye contact, and verbal communication, to get a better sense of the person's feelings or intentions.
It's essential to remember that assumptions can lead to misunderstandings, and the best approach is to communicate openly and honestly with the person involved. If you are unsure about the meaning behind the action and you are interested in knowing more, consider having a friendly conversation to clarify their intentions and feelings. Respecting personal boundaries and being sensitive to the other person's comfort level is crucial in any interaction.