tomato growing inside a tomato ,strange or what?

Garden centre

• 
  Tomato F1 Beefeater Seeds
  £4.25 at Suttons Seeds
• 
  Tomato Shirley F1 10 Seeds
  £2.99 at Jersey Plants Direct
• 
  Tomato Italian Tomato Seed Collection
  £4.99 at Suttons Seeds
• 
  Tomato F1 Tumbler Seeds
  £2.99 at Suttons Seeds
• 
  Tomato Country Taste Seeds Cordon
  £2.99 at Unwins