おは顕示欲 is not a word itself, but I kind of understand what it says.
First, おは is an extra shortened form of おはよう. It can be used alone for super casual morning greeting, or as a part of playful portmanteau like おはこんばんちは. I think it is the latter in this case.
The second part 顕示欲 is a long story. It is not an easy word, and was nor common until a (quite) while ago when experts pointed out that modern SNSes (including Twitter) were functioning as some kind of "self-esteem porn". Keywords highlighted at that time were such as 承認欲求 (Maslow's esteem needs) and 自己顕示欲 ("desire of self-display"), which soon became buzzwords mostly with a negative meaning. There might be similar terms used same way in the English-speaking world, but I am not familiar with it.
As those words gain popularity, people start to use them as a joke, as much as saying "Hi, I shamelessly need likes so do it!" Given that this is a Twitter post, the author must be fond of using the word in this way. So, in this case, the literal-ish translation would be like "morning-ostentation" or effectively saying "Morning! See my attention-seeking!"