You only see 8 Bytes while using 'whos' because this is the size of the pointer as a reference to the handle object.
To evaluate the size of a variable with such a reference, please use the command 'struct' onto this variable.
This produces a minimal overhead to the real size, but doing this you can figure out the order of magnitude of the variable.
This means image you have a variable called 'a' which shows only 8 Byte via 'whos', then do the following:
>> b = struct(a);
If you use 'whos' right now, you will see a better scale of the size of 'a' in variable 'b'.
