What does random Images flashing during mediation mean ,if anything at all?

I started meditation with Headspace app and have experienced a lot during meditation such as irrational fear of someone breaking in to the house and killing me while I was meditating , fear of snakes etc. I am off headspace for about six months now and my Vipassana practice has improved a lot. The chattering in my head has subsided but now I see lot of random images flashing while I meditate. These images don't have to mean anything but these images are nothing I have seen or imagined in my life so far. Should I wonder about their meaning or should I continue to the adage of letting it all go and focus on the moment?