Questions about neo stage 2.7

[nwfb1657]

<bmp_begin>
name: Bug-Mega
head: sprite\sys\bug_f2.bmp
small: sprite\sys\bug_s2.bmp
file(0-69): sprite\sys\bug_5.bmp w: 79 h: 79 row: 10 col: 7
file(70-139): sprite\sys\bug_6.bmp w: 79 h: 79 row: 10 col: 7
file(140-209): sprite\sys\louisEX_2.bmp w: 79 h: 79 row: 10 col: 7
file(210-214): sprite\sys\bug_7.bmp w: 107 h: 79 row: 5 col: 1
file(215-219): sprite\sys\bug_8.bmp w: 118 h: 79 row: 5 col: 1

What is the purpose of this paragraph?
file(140-209): sprite\sys\louisEX_2.bmp w: 79 h: 79 row: 10 col: 7

When the king uses D<J on the left hand side
the ball.bmp will disappear
Why?