I looked at that position, but I did not think it would stick on that surface, might have to stick one there.I'm not sure tbh. I had two, both with sticky pads, and they both look the same to me.
I just grabbed one and stuck it on. I wasn't sure how well it would grip but it's surprisingly strong - it certainly isn't coming off any time soon. And I've used the bike in hot weather, piddling rain, on motorways etc. etc.
It's also ultra convenient - the camera just clips on and off in seconds.
As for the pads.
The flat ones have rounded edges, the curved ones are square.
Flat on top, curved at the bottom in this picture.
So it looks like you used a curved one in your picture.