It appears on the cover of a book that was touted by him quite some time ago:
And if you look closely, it's not a book he's holding, it's only a cover, and at the time, he was still looking for a translator because (he said) it was written in CHINESE.
This Daily Mail story is from 2013:
BUT WITHIN THE TEXT IS THIS STATEMENT:
Even though he felt their relationship was distant, 'I hope that my brother and I can really hug each other after he's president and we can be a family again,' said Ndesandjo, who resembles Obama.
On a thread on FR you posted what looked like a number of pages from a book that were yellow and appeared aged. Did those images come from the book he's shown holding? Was it ever published? Where did you obtain those pages?
There are a number of anomalies regarding names and ages on the pages - but before we spend hours on the project of trying to identify a number of children, some of which have never been shown before, the SOURCE of the images would be appreciated.
Meet Mark Okoth Obama Ndesandjo, the China-based son of Barack Sr.s third wife. A dream about the biblical Daniel prompted him to reconnect with the president
The book was published in 2014.
I have a copy, and scanned in the pages with the pictures #19 to #25).
The other pix (#1 through #18) are from web sites.
I have copied the info from this post:
http://www.freerepublic.com/focus/chat/3407407/posts?page=187#187
here:
OK starting with the picture of Roman Obama that Lucy posted, it is from 2014, at an award ceremony.
1) Left to right, Jose, Victor, Roman Obama 2014 Jose Victor Roman photo 2RomanObamaIn2014_zpsn337djx3.png
2) Larger picture; the picture frame behind Victor is the same as your post photo WAD2014_t580RomanObama_zpse9bkwkin.jpg
3) Heres another event, in 2015; left to right Roman Obama, Miguel, Virginia Governor McAuliffe, & his aide photo Screenshot from 2015-10-13 001858_zpsj9vzkjtq.png
4) Roman Obama isnt the one with glasses; that man is IDed here and is Miguel photo Screenshot from 2015-10-13 002015_zpsyppddber.png
5) Barack Hussein Obama Sr. & Roy/Malik Obama his eldest son, pic is on wall in grannys house in Kenya photo 2dgnyuw_zpso8huq332.jpg
6) Now comparing one pic of Roy Obama, and two of Roman Obama; they are two distinct people, Roy in Kenya, Roman in Equatorial Guinea photo RoyRomanRoman_zpsjsrtc1ag.png
7) Comparing two pics of Mark Obama, one of Roy Obama, and Jose from the award pic. Three distinct people, different features and skin tone photo MarkMarkRoyRoman_zpsywmp6zxb.png
8) Comparing two pics of Mark Obama,one of Roy/Malik Obama, and Roman Obama. Three distinct people, different features and skin tone. photo MarkMarkRoyRoman_zpsqplrqa1r.png
9) Mark Obama around 2014 with advance copy of his second book; he is lighter skinned, as in #7 and #8. There is a picture of two grade school age boys on the cover. photo mark-obama-2_zpsk6mzj3hv.jpg
10) Closeup of front cover photo no94e0_zpsiti0j5oi.jpg
11) Closeup of the two boys grade school picture photo 21myakx_zpsh4znvavu.jpg
12) Comparing grade school age picture (r) with younger age (l); features of eyebrows and ears match photo 2 pix of 2 boys_zps36wejn1j.png
13) Another pose of them at younger age; note the downward pose of the head photo mark-david-photo-ali_zpsstyljodt.jpg
14) Comparing left hand younger boy and grade school boy; note angle of eyebrows and ear shape match photo Screenshot from 2015-09-26 091043_zpsyngcghua.png
15) Comparing right hand younger boy and grade school boy; note hairline peak photo v5lsgk_zpsgidhtvoe.jpg
16) Compare boy on left with the boy on right; same hair line; this is the same boy photo 28wcxzp_zpsbxbloaxt.jpg
17) Boy in picture #16 is standing here: photo nbyxzn_zpshssimhyl.jpg
18) Going back to the left hand boy in the two-boy pictures; compare the teen age kid, red background, the kid on left in middle two-boy picture, and the kid on left in right two-boy picture; it is the same boy: photo TeenToddlerGradeschoolDavid_zpsl46o4ear.png
19) Compare teen age red background pic with late teens boy in the back row left side; same person. photo Screenshot from 2016-03-12 220709_zpsfqlrvdov.png
20) Mark Obamas book with #19 four-boy picture; back row left is David, back row right is Mark. photo Page 84_zpssucukjif.jpg
21) Two boys around 1973; note left hand boys head down pose matches #13, #15, #16 pose photo Page 67_zps9qgphq9t.jpg
22) Another picture of the two boys, early 1970s photo Page 94_zps5oisnorm.jpg
23) Same boys, with older siblings at pool, 1970; older boy in front left has same head down pose as in #13, #15, #16, and #21 photo Page 53_zpsobydgchk.jpg
24) Same pool pic, with grandparents; bottom of page. Top of page is the two boys with their parents photo Page 54_zpsjqerqo63.jpg
25) The younger boys picture seen previously photo Page 83_zpsll6ddzcv.jpg