What you need to understand about depression is that it is not an emotion (like sadness): it is a condition that affects how you process information. If you tell a depressed person a joke to cheer them up, it doesn't improve their ability to process information. If anything, their inability to find joy in the joke only adds to their depression.
With depression comes the lie that you are alone and your worthlessness is completely valid and true. Being reminded that you are loved and gentle displays of affection are noticed and appreciated.
Because these gestures are not loud and boisterous, they can manage to slip under the veil of depression and not be processed incorrectly. They are little pin-pricks of light that remind the depressed person that the negative thoughts they are thinking are not Truth, that it will pass, and that they are loved for very real reasons.
So be assured: your tiny gifts are noticed.