Technically, you aren't, but R4s weren't the first devices that enabled homebrew and ROM playback on the DS. If I remember correctly, there was quite a bit of drama because of that particular game making it's way onto the internet like 3 weeks earlier, even before that years e3.
First year the DS was released they had passthrough devices... meaning it could pass DS code from the GBA slot and you could use GBA backup devices to run homebrew/pirate.
Later passthroughs were made redundant when a hacked DS firmware hit the scene. It involved shorting a protection contact on the back of the DS to install but it made it so that if a GBA device had a certain bit of code in it's header, it would automatically be loaded as a DS device.
This code was later hacked and made the first bricking program (literally displaying a brick on the screen). If you used the protected means of installing, you could reinstall... but if you didn't your device was screwed.
Later on DS slot cards started coming out. These actually had integrated DS games used to piggy back off of (which is why they were HUGE and stuck out quite a bit from the system). It wasn't till they managed to actually hack the encryption of the DS games that they were able to slim the carts down to regular DS game size.
I could go on <_< but I've already taken this off topic enough I guess.
Anyways, as others have said this one line of code doesn't mean much, if they wanted to prove it they'd have been better off displaying in the pillar boxes on the top screen. Still, will be interesting to see what, if anything, comes of this in the long term. Not many people have the hardware to install modified saves into their 3DS cards.