Here is the answer of the tricker program.

$2 =  4                     16 | 24 |
$4 = 20                     20 | 20 |
$5 = 20                     24 | 16 |

The detailed steps are described below. First the program and intial states:

        addi $2, $0, 4     # (1)              Memory
There:  sub  $4, $5, $2    # (2)        address contents
        lw   $5, 0($4)     # (3)           12  | ... |
        sw   $4, 0($5)     # (4)           16  |  24 |
        bne  $4, $5, There # (5)           20  |  20 |
                                           24  |     |
   $2 = ..., $4 = ..., $5 = 20             28  | ... | 

• (1) $2 gets 0 + 4 = 4.
• (2) $4 = $5 - $2 = 20 - 4 = 16.
• (3) $5 = value at memory address 0($4) (which is 16) = 24.
• (4) Value in $4 (which is 16) is stored at memory address 24.
• (5) $4 = 16, $5 = 24, they are not equal, go back to (2)
• (2) $4 = $5 - $2 = 24 - 4 = 20.
• (3) $5 = value at memory address 20 (0+$4 =20) = 20.
• (4) Value in $4 (=20) is stored in memory address 20 (0+$5). So 20 is stored again in address 20.
• (5) $4 = 20 and $5 = 20, so $4 equals $5, program finishes.