Its the "mom , im so much lighter i can fly" dance.
I've tried to bathe by13 month old myself but i always have to get in the tub with him and it makes such a big mess. So i have it professionally done every 2 to 3 months with the furminator package. What's funny (or not so funny) is the groomer (she's so special) is always soaking wet after bathing Dex, he leans up against her when she's bathing him, she may as well be in the tub with him. I always give her an extra tip, since this is probably my fault.
I agree he looks so much better when they bathe him plus I have no idea how to clean the anal glands.