I encountered this earlier today at an unknown road to me and despite the car on the left being fully stopped, I wasn't sure whether I could continue normally or slow/stop at the stripes.
It does not appear to have these, though. Traffic lights with no green light. (The picture if from google street walk, not a crude cut and paste exercise of mine, as it might seem) . .
At an intersection with lights as you describe it is sometimes used to indicate that in heavy traffic you should not cross that line if you cannot clear the intersection, as if the light changes you will block the traffic.
One would think that this would be self evident, I am apparently mistaken.
The little white triangles indicate 'slow down / caution' and not 'stop'. A thick white line would indicate stop. The triangles are usually placed before you enter a road / zone where you do not have priority.
In your case, maybe you were entering one these zones, and so, the driver to your left may have stopped to let you pass, since the 'priority from the right' rule applies -EXCEPT - in a roundabout where the priority is from the left.
The point was to provide a good, well detailed start to newcomers attempting the theory test.
I find it funny that there's a section in there about driving on the pavement - "give way to pedestrians". It's not unusual for me to have to get out of the way of cars or vans driving on the pavement(sidewalk)
In the OPs first example it looks to me more like a roundabout. If it's a main road and the car wants to turn into a side road then I believe they should give way to any pedestrian already crossing the road, however we were almost run down today(we had to get out of the way) in this situation by a black Mercedes with diplomatic plates.
One of the strangest things here in Switzerland is the rule that you should indicate to go around a corner (with an intersection) even if you're not actually turning off that road.