#Development Story:
No Size for iPad (only mocks are mobile and desktop)
Ambiguous on Close Button (size and position)

#Development:
Me: iPad size, should it be X?
Product Owner: Yes

#QA
QA: Close button is to Small, change to bigger
ME: (ok....)

#Product Owner Review
Product Owner: Close button to big, make it smaller, also iPad size is not that, is Y.

Me:

You know ... Every fucking time ... Where is 100 different screen colors and the sentence is ... Is not the good colors :/

Yay, the sanity-removing struggles of front-end development.
One important thing I've learned in this regard is:
You sometimes have to do it in what fits best and then make the customer, PO or whoever blievevthat it is a good idea to make it like that. Or couple it with a good reason:
"iPad users use the finger to close it, so iI've made the X large enough to make it easier to hit and users can navigate quicker"
Or sometimes it helps to make the customer feel like they've come up with the idea. It depends on the people you're dealing with, but it's always a game.

Also in the case of websites of apps:
Sometimes your customers need to be diplomatically reminded that it is NOT them who need to like the app or website, but rather their customers and that they are the actual people both of you want to attract and give a good feeling of using it.
Our customers often have their own fixated view of how something should look but it is often not what would be best for their actual customers.

Honestly, strangle your QA. They have no right to change requirements. They can advise the PO to do so because xyz but the second they start to fiddle with requirements they're failed PMs and should be removed from the evolutionary pool.