I am not sure how to interpret strumming pattern in the picture. I understand that for eights it should be following DUDUDUDU structure but the picture looks like it doesn't make a sense because of U D UDU.
What do I get wrong?
Looks suspect to me. The rhythm of the strumming hand/arm is disturbed. D-D-DUD- would be easier, and probably sound better too. Without listening to it, it's difficult to comment further.
EDIT: having had a quick listen, it's probably D--D-UDU. To keep a constant down/up movement, try DudUdUDU caps are strums, lower case ghost strums. So that second downstrum comes where an upstrum could be, but there's time either side to do it the 'wrong' way.
It looks really weird for me,i would play it like D U D D U,well yes the 8th notes are correctly DUDUDUDU,but you know you dont have to play every single note,in music we have notes and pauses, the notes that are missing are just small pauses,so you should play D(pause) U (pause) DDU in my case,it doesn't matter if you start with a downstroke or with an upstroke,well because you will be in the same time signature in any case,the only thing that changes wether you selecet to start with an Upstroke or a Downstroke is the pattern