How to assemble a byte array correctly?

Question

Java

There was a task to form an array, I have 3 values ​​\u200b\u200bthat need to be sent in one package via BLE. The first value is a letter and the two values ​​are -100 .. 100. The letter is fine, but the numbers are wrong. Previously, the numbers were sent in the following way

// left and right values ​​int -100 .. 100
value[0] = (byte) Left;
value[1] = (byte) Right;
// then value is sent over BLE

Now I send

byte[] value = new byte[3];
value[0] = (byte) 'C';
value[1] = (byte) Left;
value[2] = (byte) Right;
// then value is sent over BLE

What is the difference between the first and second case?
PS The device receives and processes everything correctly.