Some background first. I first had this style of ice tea at a Goody Goody Cafe in Kaohsiung, Taiwan. It's kind of their specialty and I didn't find anyone else doing this style of tea when I lived in Taipei. I think of it as a deconstructed milk tea. On top of regular ice tea, they float a layer of thick cream. You could just mix it up, I suppose, but I think the fun is drinking it as it's served and taking a small bit of cream with every sip. For flavored versions, they flavor the thick cream instead of the tea.
Here's a picture of the original Goody Goody version in case my description isn't helpful:
I saw that 85C was offering 2 iced teas(jasmine and green) with the thick cream served in this style. They're not on the main menu, but there's an ad for them as specials on the counter. Part of the sea salt line along with their popular sea salt coffee, the salt flavor is infused into the heavy cream which floats on top. Salt in a cold drink is a bit weird for Westerners, but trust me it's good.
I've seen pictures on menus at other boba places here in the US that looked like they could be this style of tea, but they used a light cream that just dissipated into the tea quickly. The version at 85C was the first I've found that resembled the version I had in Kaohsiung.
Since all drinks are served in to-go cups at 85C, you don't get the visual impact like you would in a tall mug. But I'd recommend taking the lid off and drinking it without a straw to get the full impact. Also bring along a napkin because you'll end up with a cream mustache.