That is the bootloader, also known as fastboot mode.
Normally you would boot into it by keeping Volume - pressed while starting or rebooting the phone.
Please confirm: When you keep Volume + pressed while starting or rebooting the phone, you don’t get into TWRP?
If so, just boot into this fastboot mode and install TWRP again … Fairphone 2 … section “Fastboot Install Method (No Root Required)”.
I still recommend 3.2.3-0 as the most reliable version.
Luckily not true.
What do you want to do with ADB?
How so?