Why notes are sometimes fatter in the Piano Roll thumbnail?

[LSMM]

Why notes are sometimes fatter in the Piano Roll thumbnail? Their length, Note Velocity or Note Panning isn't any different and I don't recognize any difference in how they sound?

[musikbear]

Why notes are sometimes fatter in the Piano Roll thumbnail?

Not understood, can you make a screenshot

[LSMM]

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[musikbear]

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