You can contribute on a few levels-
As a test engineer about testing and testability asking how (many times a day, many test setups do we need, much budget etc.), when (stage of the project, maturity of the code, etc.), who (developers, testers, automation), where (your lab ? outsource ?), what (latest master ? branches ? ) and so on...
As an Engineer having better understanding of the overall picture and processes you can step out and see what is missing, some examples- development to testing, CI, real usage scenarios, integration etc.
As an Engineer knowing something about design and coding
The bottom line is- don't feel bad sitting near experienced and smart software engineers or managers, in some areas you have better knowledge then they do.