SLM confusion

Small, large, medium - those are the breaks. That's what your images are going to be when uploaded to the venerable blogger. But what does that mean exactly? Are you describing to blogger the size of the image you are uploading? Certainly not. That would be silly - it can see for itself. After all, blogger is the one doing the uploading. So maybe SLM serve to describe how the picture will appear in the post. That's a fair guess. But does the size selection also affect the size of the image that gets displayed once it is clicked upon and is revealed in all its glory? Probably not, but due investigation is necessary.