No question that Takeda was a complex character. As to the expressions - he had a sour expression because he got some of his teeth knocked out in a spear fight, and he was embarrassed to show his mouth.
Anyway, accusations of ostentation have been made about this picture
too, but I'm not sure what either picture has to do with the issue of whether or not Ueshiba was able to successfully transmit his skills.
How old was Takeda when he got his teeth knocked out? People with teeth missing can still smile while keeping the mouth closed.
That 'picture' looks like Ueshiba pre-war to me, he didn't fully realize Aikido till post-war. I bring up the differences between Ueshiba and Takeda because they had little in common regardless of the opposite being asserted here often.
since Ueshiba quite deliberately imitated him in so many ways
This is absolutely false post-war.