Yes, cozy, and a good spot to sip single malt while listening to (as in last night) Liszt.
Ooo, dangerous to ask me about tubas. I'll try to keep it to a hundred pages. No, much bigger than a euphonium. That particular instrument is a late-50's York Master, German-made for one of the great old American manufacturers. It's now gone. The current fleet includes a Hirsbrunner HBS-193 (a very large "kaiser" contrabass tuba with rotary valves), a Holton BB-345 (much-storied--an even larger "grand orchestra" jumbo tuba with front-action piston valves), an Eastman EBB-534 (a much smaller front-piston contrabass tuba that I use for small ensembles, and that I bought to replace this York Master which was too large for that duty), a B&S Symphonie bass tuba in F with six rotary valves, a Yamaha YFB-621 bass tuba in F with four pistons and a rotary valve, and a Besson New Standard compensating euphonium from the early 70's, which is about half the size of what you see in the pic.
All of them are truly the best of their types and far better than I have the ability to explore, and I've spent 40 years amassing the collection. The Hirsbrunner was hand-hammered in Switzerland from flat brass and one of perhaps a couple of dozen that have been made in the last five decades, nearly all for professional orchestras in Germanic countries. Perhaps four or five have made it to North America. The Holton was one of at most a few hundred made in Elkhorn, Wisconsin, many of which died tragic and cruel deaths in school service, and many of which were victims of poor quality control. Mine is superb and has been carefully overhauled. Both are exceedingly rare.
Rick "you think poetry is used for audio equipment--you have no idea about musicians" Denney