Ko, there is a "virtual" circle around the focus field in the viewfinder that somewhat represents the area covered by the center weighted metering in Leica cameras that use reflected light from the shutter curtain. In the analog cameras you have a white dot in front of the curtain. With the digital metal shutters you have one segment in a brighter color to reflect the light to a photo cell on the bottom inside the body. The wider the angle of view of your lens, the more of the scene gets covered by the metering area. Basically the result is getting more unspecific the shorter the focal length you choose. You are e.g. getting more influence of the bright sky.
The nice thing about a digital camera is that you can immediately check the exposure result. The perfect tool for this evaluation of the exposure is the histogram. Learn to use it to understand if the metering was OK, i.e. resulting in a proper exposure or if the image is strongly underexposed like in your example taken with a 28mm lens. If the camera's basic metering doesn't yield a proper exposure in a difficult lighting situation, then YOU have to make a decison how to compensate to get a better exposure. You can choose to meter in a different manner, e.g. pointing down to the ground, half press and then frame with this metering result. Or you meter pointing at the scene in the same way, half press and open the aperture half or one stop.
There are cameras with multi metering scene modes that take care of this for you. A Leica M9/ M-E is not one those. That's the beauty of these primitve and basic RF cameras, you are in charge. Not some programmer who developed a fancy algorythm that gets it right in 90+% of average scenes.
If the shot is great you are resposible, if the shot sucks, then well ... you are responsible as well.😱
I like it this way and I go nuts if any instrument I use has seemingly a mind of it's own and is trying to override my intentions. If I make a seplling mistake it's my own.😀
One general remark on the "18% grey"
This is a grey that is reflecting only 18% of the light, that is actually pretty dark grey.
As for WB, yes the auto WB in the M9/M-E sucks, use manual WB (I use the expo disc) and enjoy the wonderful colors of the Leica lenses in combination with the CCD sensor ... and calibrate your monitor.😎
Cheers