This is just like your recent post with the exact same question. Momo, there is nothing wrong with these images. There does not appear to be anything wrong with your camera.
You have three things happening with these images. First, several of them are strongly back lit. Try any camera in this situation and when you have strong light like this behind your subject, yes you will get an effect of the edges of the subject "glowing" as you call it. This is very normal and not all specific to your camera or the RX100 in general. This will happen with any camera, and especially so when the aperture is wide open. In fact, using strong back lighting to get this "glowing" effect is a common technique.
Second, you are shooting all of these at F1.8. This is the widest aperture of the camera and also the aperture that yields you the shallowest depth of field in your image, which means only a very small portion of your frame is going to be in sharp focus. Without getting too detailed and to keep it simple, the only portion of the image that is going to be in focus is that which is parallel to the lens. Anything else at even the slightest of angles simply will not be in focus at this wide of an aperture. This is not only normal, this is one of the most desirable characteristics of a wide aperture; to be able blur the background to really visually separate the subject from it. Or in the case of your small figures, to even blur the edges of the figures.
The portion of the image that is not in focus will indeed appear to be "soft" and out of focus, and as you call it, glowing. This is normal for any camera shot at a wide aperture like this. I forget the model you used in you last cat shot, but that was shot at F2.8. Try setting the aperture of the RX100 to F2.8 and I think you will be amazed at how much more of your frame is in focus at F2.8 versus F1.8. If you don't like this effect, simply shoot at a higher apertures until you get the sharpness you are expecting or hoping for.
Third, shooting at 28mm or the widest angle of the lens is the focal length that is the least sharp at the edges of the frame. The closer your subject is to the edge of the frame, the more this (very minor) lack of sharpness at the frame edges will become evident.
As I explained in one of my replies to your previous post on this topic, as you are still learning about the technical aspect here and that is totally cool, the easiest way for you to see the difference between aperture settings is put the camera in P or Program Mode and turn the front control ring. This will activate the Program Shift capability of the camera and as you turn the control ring it will cycle through a variety of Aperture and Shutter Speed combinations that will yield the same exposure. I use exposure loosely here as there is much more to it than these two parameters. You can do the same thing in Aperture priority mode as well.
All of the samples that you have posted here are essentially indoor close up shots with quite less than ideal lighting conditions. The camera does perform pretty well in these less than ideal conditions, but that said we have to be reasonable with our expectations in terms what such a tiny (and relatively inexpensive) camera is capable of. The RX100 is a very fine camera indeed, but has its technical limits, as all cameras do.
Try the camera outside on a variety of shots beyond close up shots and you will likely find your images will be much improved as the light will be so much better. than in your home. If you want to shoot in Auto or in the scene modes since you are still learning, do it. Try some close ups, portraits and landscape shots. Shoot at different apertures. The point is, you can't shoot everything at F1.8 and expect the edges of things to be razor sharp. That won't happen on the RX100 or any camera for that matter.
Your images look just fine Momo. There does not appear to be anything wrong with your camera. Take it outside and experience what this little gem can do. That is a whole lot more fun than sitting at the computer, zooming into 100% to pixel peep and over analyze your images taken in poor light and searching for minor imperfections that ultimately you will find. At the end of the day, we buy these things to have fun with them right?
Schaf
