It looks as though Chloe has been active first thing this morning. Either there is more moss here or she has just rearranged it to look like that!
This is a boring part of the nesting season, as there's plenty of activity around the nest boxes, but nothing much seems to happen. They are all just filling in time before the serious business of producing their offspring starts. Normally the first egg is laid in the middle of April, so there's probably a couple of weeks to go yet!