I glad you mentioned video as I never saw it earlier
Its concerning as the angel is breathing heavy and this and eye can stem from flukes, water quality issue, eye injury or gases or microbubbles. I would take a water sample to a store that does NOT use Api kits and have them test your ammonia and nitrates and compare readings and assure your results are within safe range.
I would also consider a treatment tank with fresh mixed water and added aeration and if bulge doesnt subside in next 24 hrs, treat with Maracyn (not maracyn oxy) for at least 5 days.
Symptoms of flukes will be red or swollen gills, fish appearing to yawn, itching/ scratching on objects, hiding, rapid breathing and loss of appetite.