Why is this on my iPhone 4s screen?

This picture of a charger cord pointing to an iTunes symbol popped up randomly on my iPhone 4s and now I can't use it. It seems as if it may be asking me to connect my phone to iTunes. BUT WHY!

Is iPhone 4s still relevant?

I'm thinking of getting refurbished 64GB one for a very cheap price. Is it a good idea?

Added (1). My budget is quite limited so if I really have to dig my wallet that would get me 8GB 5C… Which is very small storage.

1st of January 1970 iPhone glitch?

I've heard about the glitch that bricks 64-bit iPhones when the date is set to 1/1/70 and then rebooted, but I want to know if it's specific to this date or if setting it to the 2nd of January 1970 will do the same.

When will I get my iPhone back from Apple?

I shipped my iPhone for a repair on Sunday for repair because it was having unexpected restarts. It's stuck on diagnosing product status.

Step 1Request
February 17, 2016: Product received by service center
Shipped via UPS with tracking number
Step 2Service
February 17, 2016: Diagnosing product
Step 3Return
Serviced product return pending

Added (1). I have a iPhone 6s Plus.

Do usb ports wear out over time? Specifically, this is a pioneer car stereo that is a few years old?

All of a sudden, its not recognizing the usb cable and saying "check usb cable" and no music will play through the cable or iphone will not charge. I tried 2 different new usb cables and same error. I've left the usb cable in the port constantly and only plugged/unplugged the phone. Did the usb port just "go bad" one day or is the system memory messed up? I tried resetting and that did not help. The usb cable and iphone work fine everywhere else.

Itunes isn't recognizing my iphone 6s?

When I plug my iphone in itunes opens up automatically like it's supposed to but then the iphone icon doesn't show up. It won't allow me to sync my phone to my computer.