It's not about putting a happy face on, but about seeing yourself as a 'depressed person' or as having depression being a core part of your identity. I think that can be harmful - and lead to weird psychologies where being depressed is more comfortable in a way, more familiar.
Being open/honest is good, but making being depressed part of the way you see 'who you are' is likely bad (imo).
Hypervigilance [0] is also a thing - and it can make things worse.