The naturalness of wood is destined to have a certain moisture content. When its water content is in balance with the water content in the air, it won't deform ... obviously, your photo frame is deformed because of water absorption. ...
We keep the wooden door unchanged and have special processing procedures ... which can be roughly divided into "natural air drying" and "artificial high heat drying" ...
As far as the wood used for wooden doors is concerned, the time of "natural air drying" is about eight months to more than one year, and the shortest time of "artificial drying" is about two weeks to one month. ...
I think the answer to your question is ... yes ... it's useless not to be straight, because it will change when it's wet and dry. ...
The paint on the outside of the wood is not only beautiful, but also moisture-proof ... Finally, I wish you all the best. ...