I saw your question and while I can't really see the plant close enough to identify what it is 100% I can suggest a couple that would be similar. The first one is Lysimachia nummularia 'Aurea' (Creeping Jenny). It's extremely fast growing...almost too fast. I only use it in containers because it's a little too aggressive in the garden. It's lime coloured foliage is excellent contrast to darker containers like the one in the photo. It also gets flowers in the spring which are nice but I really only grow it for the foliage. It drapes nicely just like the plants in the photo.
The other one I think that would work well and is super fun is Senecio rowleyanus (String of pearls). I just love this plant! Just like the name says, they are little green pearls that drip down. Senecio is a succulent and it's quite tolerant of sun or shade and watering for that matter. Google them for more info.
I have attached a photo where I have used string of pearls to drape down a tall narrow planter (planter with New Zealand Flax in the corner behind the chairs).
Creeping Jenny works well to balance taller, spiky plants, adding a lighter, brighter hue to the overall color scheme.See more ideas for working with Creeping Jenny
The straight green vertical spiky grass contrasts with the wider redwood boards and the vines flowing down the shiny surface bordered by bed of stones...all straight lines of varying widths. The accompanying comment saying that it's carefully considered is right on.