How to import pictures onto a memory card?

I have a Nikon D40 and I need to upload some photos onto the memory card. The memory card is a micro SD inside a full size SD adapter (so it can fit inside the camera). I have a mac computer, I've tried dragging the photos into the memory card folder on my desktop and it works, but then the photos don't show up in the picture library on my camera. All of my photos are on iPhoto, but I'm only trying to upload two photos, so I know the memory card is big enough. Help please!

Added (1). Both pictures are JPEGs, if thats what you're asking

Are they the same file format? Like are they both.jpg files?

Were the photos originally taken with your D40? --if not, then that *definitely* won't work.

If they were taken with the camera, they might display as long as nothing had been changed in the photo, or been manipulated in any way, including image title… But even then it's doubtful.

If you just want to load them on the camera to show them to someone, it would be simpler to email them to the person.

I would recommend using actual SDHC cards in the camera, instead of the card/adapter method… Just sayin' :-)