In US Military, if the recipient is getting a ribbon or a normal medal for honorable or meritorious service, like a good conduct medal or a purple heart, etc., the recipient stands at attention while the presenter pins the medal to his/her tunic/blouse.
If the recipient is receiving an elevated medal like the CMH, or a Navy Cross, one that hangs from a ribbon, the presenter steps to the recipient's back and fastens the ribbon at the back of the recipient's neck.
This is likely a matter of utility and ease for both presenter and recipient so it doesn't look like the presenter is going in for a big wet kiss.
As I recall, the Brits and the French require the recipient to bow deeply at the waist while the presenter affixes the ribbon at the back of the recipient's neck.
We haven't been much into all that bowing stuff on this side of the Atlantic.
Or at least we weren't until we elected a dictator. We'll have to wait and see how that shakes out.
Don't take this info to the bank, or use it to try and win a bar bet, as I am plumbing the depths of my aging memory.
So, FWIW,
Crusader Rabbit