What does interest mean here?
Though I’m not usually a fan of modern art, Piet Mondrian’s geometric paintings have
always captured my interest.
Interest noun attention or concern
interest noun a charge for borrowing money

In this context, “interest” refers to a feeling of curiosity or attention that draws someone to something. When the author mentions that Mondrian’s geometric paintings have captured their interest, it implies that these artworks have engaged their thoughts and captivated their emotions, even if they don’t generally favor modern art.

Piet Mondrian, a pioneer of abstract art, is well-known for his use of simple geometric forms and bold colors. His artistic philosophy aimed to convey harmony and order through minimalistic designs. So, even if modern art isn’t your thing, Mondrian’s unique approach may just spark a flicker of intrigue that’s hard to resist!