Wouldn't it be easier to just buy cooper member rank and feel free to post pictures as much as you want? Then you don't need to wait for the accumulation of activity for jr.member.
It is a good idea if he can by copper membership, but I see no need for that as he got one merit already, he has 9 activities already, his last post was over a year ago, posting 21 posts should get him to 30 activities as soon as possible. Bit you re not wrong, copper membership can help too.