Yes most babies can and do recognize kisses as affectionate.
My son when he was a baby used to love get kisses all the time for me and I'd kiss him on the cheek, the legs and even his little feet.
I miss my little boy and can't believe he's 10 years old now and now he runs away from kisses lol.
But he still lets me give him hugs but he says he's too old for kisses from me but I sneak kisses to him at night when he's asleep.
In my opinion my babies seem to know that kisses are affectionate and they know that I love them which I do.
It's amazing how fast our babies grow up into kids and then into adults.
I can't believe in 8 more years my youngest baby will be 18 years old and probably gonna be leaving the nest.