What is ex randomly liked my picture?

As an AI language model, I do not have any knowledge about your personal Instagram account or any of your pictures. However, if we talk in general, when an ex randomly likes your picture on social media platforms like Instagram, it can mean different things:

1. They could be trying to initiate contact with you again, and this could be their subtle way of reaching out.
2. They could just be reminiscing about memories and feeling nostalgic.
3. Maybe they genuinely like the picture and wanted to show support by liking it.
4. It could be an accident; sometimes, people accidentally double-tap while scrolling and liking a picture they didn't intend to.

Regardless of the reason behind it, if it bothers or affects you negatively, it's best to avoid over-analyzing their actions and focus on your well-being.