Is this a seroma? Should I worry? (photos)

According to your description of the problem, it is possible that you may have a seroma. It would be best to call and make an appointment with your Doctor. He may need to aspirate or replace the drain.Usually I remove the drains when drainage is less than 30cc for 48 hours.

Yes, you have a seroma. You need to see your surgeon. Let's hope they are in the same country/ state/ city as you are.
Seromas are a common but annoying complication of abdominoplasty, provided they do not become infected.
Best wishes, Mark.

Very high likelihood of seroma, which
needs to be percutaneously drained until it, dries up which could be as long as
6 weeks. If not, you can have problems such as infection or pain (which you
already have). Make sure you see your surgeon ASAP.

It is likely that you have a seroma with the amount of fluid you described prior to drain removal on day 4. Your surgeon can easily detect a fluid wave on exam and/or order an ultrasound to determine if you have a seroma. If present, the options for treatment include repeated aspiration, replacement of a drain, or opening and packing the incision.

Drain removal before infection is definitely a good idea, but not when the drainage is still 220 cc per day, especially at 4 days. I remove the drains when they are draining less than 30 cc per day. Typically the dragons come out around 8 to 14 days.  This sounds like a seroma that needs to be drained.