I do the pictures through the day too....always have. Parents love it! Also, for the first few weeks, Mom can text me as much as she needs to, until she feels comfortable. My latest texted a few times per day (each being a conversation) for the first 3 weeks, then stopped. I think it's important to them to feel that even though they can't be here for their babies, they still are involved throughout the day. It puts them at ease.
Yes i do the same as Mom of 4 said - I empathize and say that I have been there and know how hard it is but that eventually LO is going to love daycare. I remind the parents that it is just a transition period and that I am totally expecting there to be rough days at first and that the rough days are perfectly normal.
I try to seem and sound confident and every morning assure them that LO will be okay and fine and that we are going to have a good day.
I have emailed during nap time to a nervous parent to assure them or send them a picture. They really appreciate that and always feel better.
Reminding mom to keep drop offs/goodbyes brief in the morning should also make it easier for her and LO