What does the red cup with drops flashing indicate?

The Machine needs cleaning, just follow the instructions in the video link here: https://www.youtube.com/watch?v=js8vfk0W4Sc

Note: if you don't have the kit just do it with water only to switch off the red light.

You didn't indicate a specific model. So, I'm going to assume yours is relatively the same as my JWX27.

Let me start by clarifying what the red light indicates.

A solid red light indicates the cleaning cycle is in progress. A blinking red light indicates the coffeemaker is off, but due to be cleaned. When the coffeemaker is due to be cleaned, the red light will continue to blink while the coffeemaker is off until the cleaning cycle has been completed fully. The entire cleaning process takes about an hour and a half. And, it is not intuitive. So, here are my instructions.

With the coffeemaker off (with the red light blinking), pour four cups of pure white vinegar (no water added) into the reservoir. Don't short the amount. You'll need four cups to complete the cycle. Remove any filters, but leave the strainer basket in place. Tap the "select" button three times until the red light is on (and stays on, not blinking). The cleaning cycle now begins. It should take between 45 minutes and an hour to complete. Don't be concerned about the 30-minute long pause during the cycle when nothing happens. This is intentional and part of the cycle.

After the cleaning cycle has completed, get rid of the vinegar. Rinse out the strainer basket and the coffee pot. Run a full pot of clean water thru a regular brew cycle (with the pot and basket in place, of course). Then, dump the water, rinse the pot and basket again, and run another full pot of clean water thru a regular brew cycle. Dump that water too. And, you're done!

On that particular model I believe there is both a lamp indicator light and then the power indicator light. If it is lamp related the lamp indicator light (LED that looks like a sun in a cup...) would be on.

If the power indicator light is flashing red to green, that is a self diagnostic code, and you will have to contact an authorized Sony repair fascility for them to translate the problem. The error codes are not listed in the user manual, since most are not user serviceable.

Run the hot water cycle for a few seconds to prime machine.

This is warning of low oil pressure. Double check the oil level first. The next thing to check is the oil filter and make sure you have no leaks.

Pot needs cleaning. Fill reservoir with 4 cups of vinegar. Press the SELECT button until the red CLEAN indicator light turns on. Let it perk through. It will take 45-60 minutes. It brews a few cups, stops and then should brew the remainder of the vinegar. When the cycle is complete the light will burn off and the coffeemaker will turn off. Discard vinegar solution and run a couple of pots of clear water through. Hope this helps.

The red dot light flashing indicates that you have activated the child safety option so the stove will not turn on. Hold your finger on the button for at least 4 seconds to turn off the safety option.

If it is a steady light water tank is not properly in OR dregs counting and drip tray is full. Pull out the drip tray and wait for the red light changes in to flashing, then put back the drip tray.

Pot needs cleaning. Fill reservoir with 4 cups of vinegar. Press the SELECT button until the red CLEAN indicator light turns on. Let it perk through. It will take 45-60 minutes. It brews a few cups, stops and then should brew the remainder of the vinegar. When the cycle is complete the light will burn off and the coffeemaker will turn off. Discard vinegar solution and run a couple of pots of clear water through. Hope this helps.