I was told by a farmer who raised goats, that the bonding each new life makes with their mother dictates this behavior. The fawn on the left is more independent (likely didn't have a strong bond) and will exhibit this bolder behavior on subsequent encounters. The one on the right will be seen nearer his mother for comfort more often than not.
After the sibling has made his way to mom, this little one is still 'eyes on me' trying to figure things out.
I have seen this pattern over and over.
Even when this one begins to move toward mom and sibling, she is still willing to find something to eat and was willing to explore around her before joining them.