I've lived in Thailand for years. I've never been in a Thai cinema before but I've heard about the standing on national anthem practice. Thai national anthem is played everyday at 8 a.m. and 6 p.m. on TV and radio. It can be heard in coffeeshops, restaurants, shopping centres etc. with TV and radio. Everybody acts blur, eats on, drinks on, chats on or walks on, even police in uniform. The Thai king doesn't drive projects. The ministries concerned drive the projects and then invite the Thai king there to front it when they feel politically correct and expedient to do so. The Thai king portrait is hung in many (but not all) Thai homes because of his official title of Phra Chao Yu Hua, the reigning king is also the current head abbot defender of the Buddhist faith. It's usually hung along with a series of same famous past kings, e.g. Ramkhamhaeng, Chualalongkong and same famous past monks. There's no law or obligation to hang his portrait at home. Some do it as a matter of tradition and some even do it for decoration. Portraits and statues of Thai kings, past and present, are on every major road in Thailand. If everybody has to stop and stand upon seeing one, the whole Thailand would have been at a standstill.
Most Thai politicians have some military backgrounds. The military is the defender of the monarchy even though Thailand has officially constitutional monarchy since some 80 years ago. That's why there've been so many military coups in Thailand. It's to protect the position of the king when civilian politicians are winning. In countries like US, UK and even Singapore, the ministers choose their generals. In Thailand, the generals choose their ministers. Whichever party winning election, the PM and defence minister must be acceptable to the the military. The military is still all the king's men and horses. The military can do wild things and get away and their way with it, like shooting more than 100 dead in a mosque and drag their corpses out to the street for display.