I got this on second or third read, but I don’t think it gets points for execution:
Mitch asked, “What is the soccer ball doing in there?” but once I got the overall point (such as it was), I see why it’s there.
Am I being overly critical here?
Fails the first blush test
Comics I Don't Understand 
Here is the Spanish edition:
It doesn’t seem to give us anything striking. But maybe confirms my puzzlement at the soccer-ball (or fútbol-ball?) incident, which apparently is there just to contribute an is / es to Gracie’s assemblage.
Well, only in the English, which makes it likely it was written in English; in the Spanish, the es is there in the first answer, whereas in the English it’s been contracted away, so there is need for the second question.
Dunno… the “joke” seemed obvious to me.
Now *this* was a lot of work…
The girl is asking a series of inane questions and recording her brother’s answers. She then edits select words from those answers to have him saying ” grace is awesome”. The soccer ball, which is not unusual in a kid’s bedroom, is just a prop to ask a question about.
The resulting soundbite will probably sound like it was stitched together.
:-)
The movie “Thunderbird 6”, set in a future of anti-gravity airships, built the plot around pulling Gracie’s little gag with a reel-to-reel tape recorder. Based on the British TV series, which likewise did amazing things with miniatures and effects in the service of often silly scripts.
Maybe a joke in the top strip is that Baldo is enthusiastically playing football on his computer game machine with virtual players and not out with his mates using an actual football in the physical world, even though he owns one. A bit like four friends going to a restaurant where they could natter to each other but instead are all looking at their phones.
You don’t need to go through all that trouble nowadays. You just upload a few samples of the victim’s voice and tell the artificial intelligence engine what you want him to ‘say”.