It looks like you are referring to the magnifying glass icon in those screenshots.
If you are going to make the magnifying glass a button, it would be strange to have a button come before the field you are typing into. For this reason, I would put the magnifying glass on the right. To emphasize even more that it's a button you could put the icon in a box, and give it a gradient like below.
If you are using the magnifying glass as a label (e.g. to let users know this is in fact a search field), I would place it to the left as the user is more likely to see the icon when they look at the field when compared to the icon being on the right. Apple utilizes this pattern (see below).
