Is there any explanation in the game or do you have any personal theories what the cameras in the Snowdin area mean?
These cameras actually belong to Alphys!
ALPHYS: I’m Dr. Alphys. I’m ASGORE’s royal scientist! B-b-but, ahhhh, I’m not one of the “bad guys”! Actually, since you stepped out of the RUINS, I’ve, um… …been “observing” your journey through my console. Your fights… Your friendships… Everything! I was originally going to stop you, but… Watching someone on a screen really makes you root for them.
As she explains, she has been “observing” Frisk with those cameras since they left the Ruins. This is the console she uses to observe you.
Even Mettaton mentions this when the player picks the answer “The human” for the question “Who does Dr. Alphys have a crush on?”
METTATON: …SERIOUSLY? MY MY… HOW CONCEITED CAN YOU GET…? I LOVE IT! AND WHILE YOU ARE COMPLETELY WRONG, YOU DESERVE SOME CREDIT. I’VE SEEN HER WATCH YOU ON HER COMPUTER SCREEN. SMILING WHEN YOU SUCCEED. SHRIEKING WHEN YOU FAIL. AND ALWAYS, ALWAYS, WHISPERING… “NO! WRONG! YOU HAVE TO GO THAT WAY!” IN ITS OWN WAY, IS THIS NOT LOVE??