Google is testing multiple variations of the sponsored ad label in its search results. These are more subtle than the huge ad sponsored labels we saw weeks ago. Google is testing adding "by" or | or • or : between the sponsored label and the site name or domain name.
These variations were spotted by both Brodie Clark on X and posted on SERPs Alerts and Gagan Ghotra on X. I complied all the variations I saw into one graphic:
I kind of like the Sponsored by look, it seems more descriptive to me. But what do I know.