In addition to a couple of stairs on the opposite side of the pillar (on the right-side of the photo), this little ramp connects the first floor of V&A Waterfront mall with restaurants that overlook the amphitheatre, and (currently) the Wheel of Excellence.
Unless you know someone who uses a wheelchair, I guess you're unlikely to realise how difficult the simplest of navigational tasks can be. I've never had to make use of one, but from what I can see, the V&A Waterfront is pretty wheelchair-friendly. Most folk use escalators to get to the upper level of the shopping centre, but there are also lifts that you could use if you're reliant on a wheelchair. The Waterfront area has two or three major levels outside and each is accessible by wheelchair; although I can imagine that one may need some assistance to use the ramps as I imagine it's pretty tiring to scoot yourself up the incline.
In case you're traveling without a wheelchair, or for some reason require one when visiting, call 021 408 7500 (preferably a day in advance) to book one. Hire is free of charge, but requires a R50 refundable deposit.
Visit Accessible Cape Town for stacks of information that would help people with impaired mobility, vision and hearing.