Something about this photo makes it easy to imagine it in color.

Marshall Hall was still in existence until the late 1950's or early 60's. I remember taking a ferry to the park. I don't remember much about the rides, but I do recall that I was fascinated by the nickel slot machines.

As if it's a mother and her children. No sign of Dad as perhaps that's why she's in mourning. Look at the child to her left. Looks a lot like her.

From my experience in studying mourning fashion, the woman in black is in weeds, perhaps in a later stage.

If it was a more recent death, she might not appear in public at all, and if she was with family, they'd be in mourning too. But the family would not wear mourning dress for years as a wife was expected to.

The shorter veil might indicate a later stage of mourning, and she might have simply adopted black dress as the status quo for the rest of her life (As Queen Victoria did of course...)

Of course, this adherence to mourning customs is more Victorian than Edwardian or after....

People did not smile in early pictures because of the time involved in processing the pictures, there are pictures of people smiling in plenty of rather old photographs.

Consider that perhaps in the days of um, non-modern dentistry, people did not WANT to show their teeth!

The woman in the black is simply wearing the more Victorian fashion. There was a time when most women wore all black and anything colorful was either your wedding dress or your Sunday best. The younger girls are in the fashionable Edwardian clothing of the time which would be appropriate for young girls.

Also, people didn't smile deliberately in pictures back then except for racy / risque photographs. Sign of the times I guess...

[Our resident authority on Victoriana tells us the lady is wearing a mourning veil. - Dave]

Probably the same thing the hats were for- too keep the sun from burning and tanning their skin. It was very unfashionable to be tanned.

They look so unhappy :-(
Bad picnic food? Too many ants?

There's a previous picture of the 2 ladies on the right side of picture both wearing hats and dressed in white. The lady second in from right looks very much like the actress that plays the Vulcan female in the Star Trek Enterprize TV show along with Captain Archer. She has the same looking face as the actrss does. Kinda funny, I wonder if she could be any relation?

What were the 'fingerglass' gloves for?

[Um, "fingerless," not "fingerglass." - Dave]

is the woman leaning up against the tree in a state of mourning? she's radically different than the other girls picnic outfits

[I agree. Looks like widow's weeds to me. - Dave]

So fresh an beauty (and I mean the men also), so gone and old. Pity and nostalgia.