The photo shows a single, smooth swelling on the side of your neck with no redness, which together with your bigger tonsils points to a reactive lymph node from a throat infection rather than anything more serious. These nodes swell when fighting an infection nearby and usually shrink again over two to three weeks once the throat settles.
Next Steps
Warm salt-water gargles and staying hydrated will help the throat settle. Keep an eye on the lump's size over the next two weeks.
Health Tips
Please see a physician if the lump keeps growing, turns hard or fixed in place, or stays past three weeks, especially with fever or weight loss.