I've got a number of girls who look like that and are doing similar things... with the tail super skinny compared to just past the vent which looks swollen, coiling, moving back and forth from hot to cold - one has even pushed her house back and forth around the cage, like it just isn't "feng shui" enough for her :)
From my experience, it means laying will happen soon - but you can't even say it will be tomorrow - or even this week! They'll drop em when they are ready, just keep checking on her in the mornings (they usually lay overnight or in the morning) and be ready for it. I've been waiting on two girls to lay for a while who have been swollen and uncomfortable, looking like they'll pop a bit, but they just aren't really wanting to let go of their eggs just yet :) One of those girls I checked this morning and felt her belly (well more like where her uterus is) and she's so swollen, I can't believe she hasn't dropped those eggs yet :)