Job Description on Approved LC - for AC21

[myitneeds]

Job Description on Approved LC - for AC21

Gurus, Please clear my doubt.

1. Is that Item 13 is Job description in LC ( GC card LC ) ?
( I do not know what job description in Paper Advertisement ? Is that usally same advertised ? - EB3 )

2. IF so, For changing employer using AC 21, is that same job description should match to Item 13 for new job at new employer ??

Thanks in advance