Mark Hamill Tweets Picture From 'Episode VIII' Set

We know Luke Skywalker's role in Star Wars Episode VIII will be far larger than it was in The Force Awakens, meaning Mark Hamill will have to spend a lot more time on set.  Hamill was on set today and tweeted a picture of a visitor he had (his daughter's dog).  Check it out below,

What's interesting is that this is the second picture from the set to confirm the film's working title, "Space Bear: Episode VIII".  Hamill's co-star, Carrie Fisher also tweeted a picture of her dog seated on her "Speace Bear" chair on set.  (I'm beginning to sense a them here, should we be on the look out for more pets on set?)