Andrew was momentarily blinded by the machine's lights so he can't watch was happening to his body. However he definitely can feel that something was changing, or in better words, he felt he was getting bigger in everywhere.
When the lights faded away, Andrew immediately noticed that his former skinny and hairless arm now was beefy and covered in a thick layer of hair. He can't believe it! He changed!
He tried to stand up but he noticed that he was way more heavy, he looked down and watched a huge hairy belly, two hairy moobs, etcetera. He was astounded, that body was completely different from his former self. He even had black body hair instead of his usual blonde.
He looked at the machine's screen and discovered that the device had determined he will be a hairy bear now. The amount of fat and body hair was unnatural for a teenager, so he assumed the machine had also made him older. How much, he didn't know but he definitely was beyond his thirties.
Fortunately, the machine also altered his clothes, so he won't be naked, but his former casual teen style now looked very cringey on his new shape. Especially those shorts that now weren't long enough to cover his fat and hairy thighs. Or his flip flops which weren't doing anything to hide the hairs on his feet or his yellowed toe nails.
Andrew wondered if the machine only altered his current clothes or it has also altered reality. If that's the case, maybe he could find better fitting clothes in his home. That's why he decided to leave the arcade as soon as he could.
On his way home, he noticed that his stamina was also lower, because he got tired after a few minutes. He noticed that a bus was coming and he decided to take it. On board, he looked at his wallet and noticed that it was still showing his driver license where he looked exactly the same. He worried that maybe reality hadn't changed.
While he was still going home in the bus, he wondered if it was a good idea. His parents could freak out and call the police, or something worse. He needed to take a choice immediately.