IOS – How to force passcode unlock on iPhone SE lock screen

What do you mean by "I don't know how to unlock it and even if I did, I can't: half of the screen looks like a matrix" ?

Do you mean you actually do know how to unlock it but can't because the screen is damaged? Or do you mean you can't because you've forgotten your passcode? Or do you mean something else?

We may be able to help if you provide full details of your situation and what you've already tried.

For example, have you tried any of the following:

1. Restarting your device by holding down both the power button and pressing down on where the home button should be for at least 10 secs until the Apple logo appears?
2. Double tapping on the slider to see what happens?
3. Connecting your device to your computer after launching iTunes?
4. Connecting your device to your computer and running your photo software to see if you can transfer your photos?

Also, is your device set up to use photo stream on iCloud? If so, your photos may already be accessible via iCloud from another device, so you may not need to transfer them from the iPhone.

Please provide as much info as you can.

Everything you've described is exactly how it works in iOS 10, with one exception (noted in the third paragraph).

Pressing the home button once goes to the lock screen. Note that if you're using a 6s or later, the Touch ID sensor is so sensitive that pressing the home button with a registered Touch ID finger generally leads to the device going directly to the home screen. This has been the case since the 6s (and iOS 9) came out.

The new Raise to Wake feature in iOS 10 allows you to raise the device towards you to turn on the lock screen without pressing any buttons. I've noticed that it will turn the screen back off rather quickly if you don't start interacting with it nearly immediately.

Resting your finger on the home button unlocks the phone. The only change is that instead of going to the home screen, unlocking now stays on the lock screen but provides additional functionality since it's unlocked. You can override it staying on the lock screen by toggling Settings > General > Accessibility > Home Button > Rest for Unlock.

Pressing the home button twice does take you to the passcode screen where you can use Touch ID or enter your passcode. Again, if you use a Touch ID registered finger, it will likely unlock the device by accident, and this has been the case since the iPhone 6s debuted.